JP2022018485A - Method for forming resist underlayer film and pattern forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist underlayer film or the like having excellent performance such as etching resistance.
SOLUTION:
A step of applying a composition containing a material for forming a resist underlayer film selected from the group consisting of an aromatic compound or a resin thereof onto a substrate, and a step of applying the composition.
A preheat treatment step of heating the applied composition at 50 ° C to 300 ° C, and
After the preheat treatment step, a heat treatment step of heating at a temperature of 400 ° C. or higher and lower than 800 ° C. in an inert gas atmosphere having an oxygen concentration of less than 5%
A method for forming a resist underlayer film, including.
[Selection diagram] None

Description

The present invention relates to a method for forming a resist underlayer film and a method for forming a pattern.

In recent years, with the increasing integration and speed of semiconductor devices, miniaturization of pattern rules has been required. In lithography using optical exposure, which is currently used as a general-purpose technology, the light source used is used. Various technological developments have been made on how to perform fine and high-precision pattern processing.

As a light source for lithography used when forming a resist pattern, light exposure using a mercury lamp g-line (436 nm) or i-line (365 nm) as a light source is widely used in a portion having a low degree of integration. On the other hand, lithography using a shorter wavelength KrF excimer laser (248 nm) and ArF excimer laser (193 nm) has also been put into practical use in areas where the degree of integration is high and miniaturization is required, and the cutting-edge generation that requires further miniaturization. Then, lithography using extreme ultraviolet (EUV, 13.5 nm) is approaching practical use.

As the resist pattern becomes thinner in this way, in the single-layer resist method used as a typical resist pattern forming method, the ratio of the height of the pattern to the pattern line width (aspect ratio) increases, and the developer during development It is well known that the surface tension of the pattern causes the pattern to collapse. Therefore, in order to form a pattern with a high aspect ratio on a stepped substrate, it is known that a multilayer resist method in which films having different dry etching characteristics are laminated to form a pattern is excellent, and a photoresist using a silicon-containing photosensitive polymer is known to be excellent. A two-layer resist method (see, for example, Patent Document 1) in which a layer is combined with an organic polymer containing carbon, hydrogen, and oxygen as main constituent elements, for example, a lower layer made of a novolak polymer, or an organic system used in a single-layer resist method. A three-layer resist method (see, for example, Patent Document 2) in which a photoresist layer made of a photosensitive polymer and an intermediate layer made of a silicon-based polymer or a silicon-based CVD film and a lower layer made of an organic polymer are combined has been developed.

In this three-layer resist method, first, a pattern of the photoresist layer is transferred to a silicon-containing intermediate layer using a fluorocarbon-based dry etching gas, and then the pattern is used as a mask and carbon and hydrogen are mainly used by the oxygen-containing gas. The pattern is transferred to the organic underlayer film as a constituent element by dry etching, and the pattern is formed on the substrate to be processed by dry etching using this as a mask. However, in the semiconductor device manufacturing process of the 20 nm generation or later, when the organic underlayer film pattern is transferred to the substrate to be processed by dry etching using this organic underlayer film pattern as a hard mask, a phenomenon is observed in which the underlayer film pattern is twisted or bent.

As the carbon hard mask formed directly on the substrate to be processed, an amorphous carbon (hereinafter CVD-C) film prepared by a CVD method using methane gas, ethane gas, acetylene gas or the like as raw materials is generally used. It is known that this CVD-C film can extremely reduce the number of hydrogen atoms in the film and is very effective against the above-mentioned pattern twisting and bending, but it is a substrate to be processed as a base. It is also known that when there is a step in the surface, it is difficult to embed such a step flat due to the characteristics of the CVD process. Therefore, when a substrate to be processed with a step is embedded with a CVD-C film and then patterned with a photoresist, a step is generated on the coated surface of the photoresist due to the influence of the step on the substrate to be processed, and therefore the thickness of the photoresist increases. It becomes non-uniform, and as a result, the focal margin and the pattern shape at the time of lithography deteriorate.

On the other hand, it is known that when the underlayer film as a carbon hard mask formed directly on the substrate to be processed is formed by the spin coating method, there is an advantage that the step of the stepped substrate can be embedded flat. When the substrate is flattened with this underlayer film material, fluctuations in the film thickness of the silicon-containing intermediate layer and photoresist formed on the substrate are suppressed, the focal margin of lithography can be expanded, and a normal pattern is formed. can.

Therefore, an underlayer material and an underlayer film that can be formed by a spin coating coating method that has high etching resistance and can form a film having high flatness on the substrate to be processed are formed when the substrate to be processed is dry-etched. There is a need for a way to do this.

Generally, a material having a large carbon content is used for the resist underlayer film. When such a material having a high carbon content is used for the resist underlayer film, the etching resistance during substrate processing is improved, and as a result, more accurate pattern transfer becomes possible. As such a resist underlayer film, a thermosetting phenol novolac resin is well known (see, for example, Patent Document 1). Further, it is known that a resist underlayer film formed of a resist underlayer film forming composition containing an acenaphthylene-based polymer exhibits good properties (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2000-143937 Japanese Unexamined Patent Publication No. 2001-40293

With the further miniaturization of the etching pattern, there is a problem of pattern transfer due to insufficient etching resistance of the resist underlayer film, and further improvement of etching resistance is required. In view of the standards required in recent years, the underlayer film obtained by the techniques described in Patent Documents 1 and 2 still has an etching resistance (hereinafter, simply referred to as "etching resistance") when a fluorocarbon-based gas is used. There is room for improvement.

The present invention has been made in view of the above circumstances. That is, an object of the present invention is to provide a method for forming a resist underlayer film and a method for forming a pattern, which can form a resist underlayer film having excellent etching resistance.

In view of the above circumstances, the present inventors have conducted diligent research and found that the above problems can be solved by carrying out a specific preliminary heat treatment and a subsequent heat treatment, and to complete the present invention. I arrived.

（式（１Ａ）中、Ｘは酸素原子、硫黄原子、単結合又は無架橋であり、Ｒ^aは炭素数１～４０の２ｎ価の基又は単結合であり、Ｒ^bは各々独立して、置換基を有していてもよい炭素数１～４０のアルキル基、置換基を有していてもよい炭素数６～４０のアリール基、置換基を有していてもよい炭素数２～４０のアルケニル基、置換基を有していてもよい炭素数２～４０のアルキニル基、置換基を有していてもよい炭素数１～４０のアルコキシ基、ハロゲン原子、チオール基又は水酸基であり、ｍは各々独立して０～９の整数であり、ｎは１～４の整数であり、ｐは各々独立して０～２の整数である。ここで、Ｒ^bの少なくとも１つは水酸基及びチオール基から選ばれる１種を含む基であり、すべてのｍが同時に０となることはない。）

（式（２Ａ）中、Ｘ、Ｒ^a、Ｒ^b、ｎ及びｐは、前記式（１Ａ）において説明したものと同義であり、Ｒ^cは単結合又は炭素数１～４０のアルキレン基であり、ｍ²は各々独立して０～８の整数である。ここで、Ｒ^bのうち、少なくとも１つは水酸基及びチオール基から選ばれる１種以上を含む基であり、すべてのｍ²が同時に０となることはない。）
［４］
前記樹脂が、式（１Ｂ）で表される芳香族ヒドロキシ化合物に由来する繰り返し単位を有する多環ポリフェノール樹脂であって、前記繰り返し単位同士が、芳香環同士の直接結合によって連結している多環ポリフェノール樹脂を含む、［１］又は［２］に記載のレジスト下層膜の形成方法。

（式（１Ｂ）中、Ａはベンゼン環又は縮合環を表す。さらに、Ｒ⁰は各々独立して、置換基を有していてもよい炭素数１～４０のアルキル基、置換基を有していてもよい炭素数６～４０のアリール基、置換基を有していてもよい炭素数２～４０のアルケニル基、置換基を有していてもよい炭素数２～４０のアルキニル基、置換基を有していてもよい炭素数１～４０のアルコキシ基、ハロゲン原子、チオール基又は水酸基であり、ここで、Ｒ⁰の少なくとも１つは水酸基であり、ｍは０～９の整数である。）
［５］
前記式（１Ａ）で表される化合物が、下記式（１）で表される化合物である、［３］に記載のレジスト下層膜の形成方法。

（式（１）中、Ｘ、ｍ、ｎ及びｐは前記式（１Ａ）において説明したものと同義であり、Ｒ¹は前記式（１Ａ）におけるＲ^aと同義であり、Ｒ²は各々独立して、炭素数１～４０のアルキル基、炭素数６～４０のアリール基、炭素数２～４０のアルケニル基、炭素数１～４０のアルコキシ基、ハロゲン原子、チオール基又は水酸基であり、ここで、Ｒ²の少なくとも１つは水酸基又はチオール基であり、すべてのｍが同時に０となることはない。）
［６］
前記式（１）で表される化合物が、下記式（１－１）で表される化合物である、［５］に記載のレジスト下層膜の形成方法。

（式（１－１）中、Ｚは酸素原子又は硫黄原子であり、Ｒ¹、Ｒ²、ｍ、ｐ及びｎは前記式（１）において説明したものと同義である。ここで、Ｒ²の少なくとも１つは水酸基及びチオール基から選ばれる１種であり、すべてのｍが同時に０となることはない。）
［７］
前記式（１－１）で表される化合物が、下記式（１－２）で表される化合物である、［６］に記載のレジスト下層膜の形成方法。

（式（１－２）中、Ｒ¹、Ｒ²、ｍ、ｐ及びｎは前記式（１）において説明したものと同義である。ここで、Ｒ²の少なくとも１つは水酸基又はチオール基であり、すべてのｍが同時に０となることはない。）
［８］
前記式（１－２）で表される化合物が、下記式（１－３）で表される化合物である、［７］に記載のレジスト下層膜の形成方法。

（式（１－３）中、Ｒ¹、ｐ及びｎは、前記式（１）で説明したものと同義であり、Ｒ⁴は各々独立して、炭素数１～４０のアルキル基、炭素数６～４０のアリール基、炭素数２～４０のアルケニル基、炭素数２～４０のアルキニル基、炭素数１～４０のアルコキシ基、ハロゲン原子又はチオール基であり、ｍ⁴は、各々独立して０～８の整数であり、ｑは、各々独立して０～８の整数である。ここで、すべてのｑが同時に０となることはない。）
［９］
前記式（１－３）で表される化合物が、下記式（１－４）で表される化合物である、［８］に記載のレジスト下層膜の形成方法。

（式（１－４）中、Ｒ¹、ｐ及びｎは上記式（１）で説明したものと同義であり、Ｒ⁴は上記式（１－３）で説明したものと同義であり、ｍ⁴′は、各々独立して０～７の整数である。）
［１０］
前記式（１－４）で表される化合物が、下記式（１－５）で表される化合物である、［９］に記載のレジスト下層膜の形成方法。

（上記式（１－５）中、Ｒ¹は前記式（１）で説明したものと同義であり、Ｒ⁴は前記式（１－３）で説明したものと同義であり、ｍ⁴′′は各々独立して、０～５の整数である。）
［１１］
前記式（１Ａ）で表される化合物が、下記式（３）で表される化合物である、［３］に記載のレジスト下層膜の形成方法。

（式（３）中、Ｒ¹は前記式（１Ａ）におけるＲ^aと同義であり、ｎ及びｐは前記式（１Ａ）において説明したものと同義であり、Ｒ⁵及びＲ⁶は各々独立して炭素数１～４０のアルキル基、炭素数６～４０のアリール基、炭素数２～４０のアルケニル基、炭素数１～４０のアルコキシ基、ハロゲン原子、チオール基又は水酸基であり、ｍ⁵は各々独立して０～８の整数であり、ｍ⁶は各々独立して０～９の整数である。ここで、Ｒ⁵及びＲ⁶から選ばれる少なくとも１つは水酸基及びチオール基から選ばれる１種であり、すべてのｍ⁵及びｍ⁶が同時に０となることはない。）
［１２］
前記式（３）で表される化合物が、下記式（３－１）で表される化合物である、［１１］に記載のレジスト下層膜の形成方法。

（式（３－１）中、Ｒ¹、Ｒ⁵、Ｒ⁶及びｎは、前記式（３）において説明したものと同義であり、ｍ^5'は各々独立して０～４の整数であり、ｍ^6'は各々独立して０～５の整数である。ここで、Ｒ⁵及びＲ⁶から選ばれる少なくとも１つは水酸基及びチオール基から選ばれる１種であり、すべてのｍ^5'及びｍ^6'が同時に０となることはない。）
［１３］
前記式（３－１）で表される化合物が、下記式（３－２）で表される化合物である、［１２］に記載のレジスト下層膜の形成方法。

（式（３－２）中、Ｒ¹は前記式（３）で説明したものと同義であり、Ｒ⁷及びＲ⁸は各々独立して炭素数１～４０のアルキル基、炭素数６～４０のアリール基、炭素数２～４０のアルケニル基、炭素数２～４０のアルキニル基、炭素数１～４０のアルコキシ基、ハロゲン原子、チオール基又は水酸基であり、ｍ⁷及びｍ⁸は各々独立して０～７の整数である。）
［１４］
前記式（２Ａ）で表される構造を有する樹脂が、下記式（２）で表される構造を有する樹脂である、［３］に記載のレジスト下層膜の形成方法。

（式（２）中、Ｘ、Ｒ¹、Ｒ²、ｎ及びｐは前記式（１）において説明したものと同義であり、Ｒ³は前記式（２Ａ）におけるＲ^cと同義であり、ｍ²は前記式（２Ａ）において説明したものと同義である。ここで、Ｒ²の少なくとも１つは水酸基及びチオール基から選ばれる１種であり、すべてのｍ²が同時に０となることはない。）
［１５］
前記式（２）で表される構造を有する樹脂が、下記式（２－１）で表される構造を有する樹脂である、［１４］に記載のレジスト下層膜の形成方法。

（式（２－１）中、Ｚは前記式（１－１）で説明したものと同義であり、Ｒ¹、Ｒ²、Ｒ³、ｍ²、ｐ及びｎは前記式（２）において説明したものと同義であり、ここで、Ｒ²の少なくとも１つは水酸基及びチオール基から選ばれる１種であり、すべてのｍ²が同時に０になることはない。）
［１６］
前記式（２）又は（２－１）で表される構造を有する樹脂において、Ｒ³が単結合であり、当該Ｒ³により芳香環同士が直接結合で連結されている、［１４］又は［１５］に記載のレジスト下層膜の形成方法。
［１７］
前記式（２Ａ）で表される構造を有する樹脂が、下記式（４）で表される構造を有する樹脂である、［３］に記載のレジスト下層膜の形成方法。

（式（４）中、Ｒ¹、ｐ及びｎは、上記式（２Ａ）で説明したものと同義であり、Ｒ⁵及びＲ⁶は各々独立して炭素数１～４０のアルキル基、炭素数６～４０のアリール基、炭素数２～４０のアルケニル基、炭素数１～４０のアルコキシ基、ハロゲン原子、チオール基又は水酸基であり、ｍ⁵は各々独立して０～８の整数であり、ｍ⁶は各々独立して０～９の整数である。ここで、Ｒ⁵及びＲ⁶から選ばれる少なくとも１つは水酸基及びチオール基から選ばれる１種であり、すべてのｍ⁵及びｍ⁶が同時に０となることはない。Ｒ³は前記式（２Ａ）におけるＲ^cと同義である。）
［１８］
前記式（４）で示される構造を有する樹脂において、Ｒ³が単結合であり、当該Ｒ³により芳香環同士が直接結合で連結されている、［１７］に記載のレジスト下層膜の形成方法。
［１９］
前記Ｒ^A又はＲ¹が、Ｒ^A－Ｒ^Bで表される基であり、ここで、当該Ｒ^Aはメチン基であり、当該Ｒ^Bは置換基を有していてもよい炭素数が６～３０のアリール基である、［３］，［５］～［１８］のいずれかに記載のレジスト下層膜の形成方法。
［２０］
前記式（１Ｂ）中のＡが、縮合環である、［４］に記載のレジスト下層膜の形成方法。
［２１］
前記樹脂が、架橋反応性のある化合物に由来する変性部分をさらに有する、［１］～［２０］のいずれかに記載のレジスト下層膜の形成方法。
［２２］
前記架橋反応性のある化合物が、アルデヒド類又はケトン類である、［２１］に記載のレジスト下層膜の形成方法。
［２３］
前記樹脂の重量平均分子量が１０００～１０００００である、［１］～［２２］のいずれかに記載のレジスト下層膜の形成方法。
［２４］
［１］～［２３］のいずれかに記載のレジスト下層膜の形成方法により、前記基板上に前記レジスト下層膜を形成する工程と、
珪素原子を含有する中間層形成用組成物を前記レジスト下層膜上に塗布し、ベークすることにより珪素含有中間層を形成する工程と、
前記珪素含有中間層上にレジスト膜を形成する工程と、
前記レジスト膜に対し少なくとも露光及び現像してレジストパターンを形成する工程と、
前記レジストパターンをマスクとして、フルオロカーボンを含むガスを用いて前記珪素含有中間層をドライエッチングする工程と、
を含む、パターン形成方法。 That is, the present invention includes the following aspects.
[1]
A step of applying a composition containing a material for forming a resist underlayer film selected from the group consisting of an aromatic compound or a resin thereof onto a substrate, and a step of applying the composition.
A preheat treatment step of heating the applied composition at 50 ° C. or higher and 300 ° C. or lower, and
After the preheat treatment step, a heat treatment step of heating at a temperature of 400 ° C. or higher and lower than 800 ° C. in an inert gas atmosphere having an oxygen concentration of less than 5%
A method for forming a resist underlayer film, including.
[2]
The method for forming a resist underlayer film according to [1], wherein the composition is heated in the atmosphere of an inert gas having an oxygen concentration of less than 5% in the preheat treatment step.
[3]
The aromatic compound is a compound represented by the following formula (1A), and / or the resin is a resin having a structure represented by the following formula (2A), [1] or [2]. The method for forming a resist underlayer film according to the above.

(In the formula (1A), X is an oxygen atom, a sulfur atom, a single bond or no cross-linking, R ^a is a 2n-valent group or a single bond having 1 to 40 carbon atoms, and R ^b is independent of each other. An alkyl group having 1 to 40 carbon atoms which may have a substituent, an aryl group having 6 to 40 carbon atoms which may have a substituent, and 2 to 40 carbon atoms which may have a substituent. An alkenyl group, an alkynyl group having 2 to 40 carbon atoms which may have a substituent, an alkoxy group having 1 to 40 carbon atoms which may have a substituent, a halogen atom, a thiol group or a hydroxyl group. m is an independently integer of 0 to 9, n is an integer of 1 to 4, and p is an independently of an integer of 0 to 2. where at least one of R ^b is a hydroxyl group and It is a group containing one selected from thiol groups, and not all m becomes 0 at the same time.)

(In the formula (2A), X, R ^a , R ^b , n and p are synonymous with those described in the above formula (1A), and R ^c is a single bond or an alkylene group having 1 to 40 carbon atoms. , M ² are independently integers from 0 to 8. Here, at least one of R ^b is a group containing at least one selected from a hydroxyl group and a thiol group, and all m ² are simultaneously. It will never be 0.)
[4]
The resin is a polycyclic polyphenol resin having a repeating unit derived from an aromatic hydroxy compound represented by the formula (1B), and the repeating units are linked by a direct bond between the aromatic rings. The method for forming a resist underlayer film according to [1] or [2], which comprises a polyphenol resin.

(In the formula (1B), A represents a benzene ring or a condensed ring. Further, R ⁰ independently has an alkyl group having 1 to 40 carbon atoms and a substituent which may have a substituent. An aryl group having 6 to 40 carbon atoms which may be present, an alkenyl group having 2 to 40 carbon atoms which may have a substituent, an alkynyl group having 2 to 40 carbon atoms which may have a substituent, and a substituent. It is an alkoxy group, a halogen atom, a thiol group or a hydroxyl group having 1 to 40 carbon atoms which may have a group, where at least one of R ⁰ is a hydroxyl group and m is an integer of 0 to 9. .)
[5]
The method for forming a resist underlayer film according to [3], wherein the compound represented by the formula (1A) is a compound represented by the following formula (1).

(In the formula (1), X, m, n and p are synonymous with those described in the above formula (1A), R ¹ is synonymous with R ^a in the above formula (1A), and R ² is independent of each other. An alkyl group having 1 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a halogen atom, a thiol group or a hydroxyl group. At least one of R ² is a hydroxyl group or a thiol group, and not all m are zero at the same time.)
[6]
The method for forming a resist underlayer film according to [5], wherein the compound represented by the formula (1) is a compound represented by the following formula (1-1).

(In the formula (1-1), Z is an oxygen atom or a sulfur atom, and R ¹ , R ² , m, p and n are synonymous with those described in the above formula (1). Here, R ² is used. At least one of them is one selected from a hydroxyl group and a thiol group, and not all m becomes 0 at the same time.)
[7]
The method for forming a resist underlayer film according to [6], wherein the compound represented by the formula (1-1) is a compound represented by the following formula (1-2).

(In the formula (1-2), R ¹ , R ² , m, p and n are synonymous with those described in the above formula (1). Here, at least one of R ² is a hydroxyl group or a thiol group. Yes, not all m's are 0 at the same time.)
[8]
The method for forming a resist underlayer film according to [7], wherein the compound represented by the formula (1-2) is a compound represented by the following formula (1-3).

(In the formula (1-3), R ¹ , p and n are synonymous with those described in the above formula (1), and R ⁴ is an alkyl group having 1 to 40 carbon atoms and the number of carbon atoms, respectively. It is an aryl group of 6 to 40, an alkenyl group having 2 to 40 carbon atoms, an alkynyl group having 2 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a halogen atom or a thiol group, and m ⁴ is independent of each other. It is an integer of 0 to 8, and q is an integer of 0 to 8 independently. Here, not all qs are 0 at the same time.)
[9]
The method for forming a resist underlayer film according to [8], wherein the compound represented by the formula (1-3) is a compound represented by the following formula (1-4).

(In the formula (1-4), R ¹ , p and n are synonymous with those described in the above formula (1), and R ⁴ is synonymous with the one described in the above formula (1-3). ⁴ ′ is an integer of 0 to 7 independently.)
[10]
The method for forming a resist underlayer film according to [9], wherein the compound represented by the formula (1-4) is a compound represented by the following formula (1-5).

(In the above formula (1-5), R ¹ is synonymous with the one described in the above formula (1), and R ⁴ is synonymous with the one described in the above formula (1-3), m ⁴ ″. Are independently integers from 0 to 5.)
[11]
The method for forming a resist underlayer film according to [3], wherein the compound represented by the formula (1A) is a compound represented by the following formula (3).

(In the formula (3), R ¹ is synonymous with R ^a in the formula (1A), n and p are synonymous with those described in the formula (1A), and R ⁵ and R ⁶ are independent of each other. It is an alkyl group having 1 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a halogen atom, a thiol group or a hydroxyl group, and m ⁵ is Each is an independently integer from 0 to 8, and m ⁶ is an independent integer from 0 to 9. where at least one selected from R ⁵ and R ⁶ is selected from a hydroxyl group and a thiol group. It is a species, and not all m ⁵ and m ⁶ are 0 at the same time.)
[12]
The method for forming a resist underlayer film according to [11], wherein the compound represented by the formula (3) is a compound represented by the following formula (3-1).

(In Eq. (3-1), R ¹ , R ⁵ , R ⁶ and n are synonymous with those described in Eq. (3), and m ^5'is an integer of 0 to 4 independently. , M ^6'are independently integers from 0 to 5. where at least one selected from R ⁵ and R ⁶ is one selected from hydroxyl and thiol groups, all m ^5'and. m ^6'cannot be 0 at the same time.)
[13]
The method for forming a resist underlayer film according to [12], wherein the compound represented by the formula (3-1) is a compound represented by the following formula (3-2).

(In the formula (3-2), R ¹ has the same meaning as that described in the above formula (3), and R ⁷ and R ⁸ are independently alkyl groups having 1 to 40 carbon atoms and 6 to 40 carbon atoms, respectively. Aryl group, alkenyl group having 2 to 40 carbon atoms, alkynyl group having 2 to 40 carbon atoms, alkoxy group having 1 to 40 carbon atoms, halogen atom, thiol group or hydroxyl group, and m ⁷ and m ⁸ are independent of each other. It is an integer from 0 to 7.)
[14]
The method for forming a resist underlayer film according to [3], wherein the resin having the structure represented by the formula (2A) is the resin having the structure represented by the following formula (2).

(In the formula (2), X, R ¹ , R ² , n and p are synonymous with those described in the above formula (1), R ³ is synonymous with R ^c in the above formula (2A), and m. ² is synonymous with that described in the above formula (2A). Here, at least one of R ² is one selected from a hydroxyl group and a thiol group, and all m ² are not 0 at the same time. .)
[15]
The method for forming a resist underlayer film according to [14], wherein the resin having the structure represented by the formula (2) is a resin having the structure represented by the following formula (2-1).

(In the formula (2-1), Z has the same meaning as that described in the above formula (1-1), and R ¹ , R ² , R ³ , m ² , p and n are described in the above formula (2). Here, at least one of R ² is one selected from a hydroxyl group and a thiol group, and not all m ² become 0 at the same time.)
[16]
In the resin having the structure represented by the formula (2) or (2-1), R ³ is a single bond, and the aromatic rings are directly bonded to each other by the R ³ [14] or [ 15] The method for forming a resist underlayer film.
[17]
The method for forming a resist underlayer film according to [3], wherein the resin having the structure represented by the formula (2A) is the resin having the structure represented by the following formula (4).

(In the formula (4), R ¹ , p and n are synonymous with those described in the above formula (2A), and R ⁵ and R ⁶ are independently alkyl groups having 1 to 40 carbon atoms and carbon atoms, respectively. It is an aryl group of 6 to 40, an alkenyl group having 2 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a halogen atom, a thiol group or a hydroxyl group, and m ⁵ is an independently integer of 0 to 8. m ⁶ is an independently integer from 0 to 9. Here, at least one selected from R ⁵ and R ⁶ is one selected from a hydroxyl group and a thiol group, and all m ⁵ and m ⁶ are selected. It does not become 0 at the same time. R ³ is synonymous with R ^c in the above equation (2A).)
[18]
The method for forming a resist underlayer film according to [17], wherein in the resin having the structure represented by the formula (4), R ³ is a single bond and the aromatic rings are directly bonded to each other by the R ³ . ..
[19]
The ^RA or ^{R 1} is a group represented by RA ^- RB, where the ^RA is a methine group, and the ^RB may have a substituent and has 6 carbon atoms. The method for forming a resist underlayer film according to any one of [3], [5] to [18], which is an aryl group of up to 30.
[20]
The method for forming a resist underlayer film according to [4], wherein A in the formula (1B) is a condensed ring.
[21]
The method for forming a resist underlayer film according to any one of [1] to [20], wherein the resin further has a modified portion derived from a crosslink-reactive compound.
[22]
The method for forming a resist underlayer film according to [21], wherein the crosslinkable compound is an aldehyde or a ketone.
[23]
The method for forming a resist underlayer film according to any one of [1] to [22], wherein the resin has a weight average molecular weight of 1000 to 100,000.
[24]
The step of forming the resist underlayer film on the substrate by the method for forming the resist underlayer film according to any one of [1] to [23], and the step of forming the resist underlayer film.
A step of applying a composition for forming an intermediate layer containing a silicon atom onto the resist underlayer film and baking the composition to form a silicon-containing intermediate layer.
The step of forming a resist film on the silicon-containing intermediate layer and
A step of forming a resist pattern by at least exposing and developing the resist film.
A step of dry etching the silicon-containing intermediate layer using a gas containing fluorocarbon using the resist pattern as a mask.
A pattern forming method including.

According to the present invention, it is possible to provide a resist underlayer film or the like having excellent performance such as etching resistance.

Hereinafter, embodiments for carrying out the present invention (hereinafter, simply referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be appropriately modified and carried out within the scope of the gist thereof.

<Method of forming resist underlayer film>
The method for forming a resist underlayer film according to the present embodiment includes a step of applying a composition containing a resist underlayer film forming material selected from the group consisting of an aromatic compound or a resin thereof onto a substrate, and the applied composition. A preheat treatment step of heating an object at 50 ° C. or higher and 300 ° C. or lower, and a heat treatment step of heating the material at a temperature of 400 ° C. or higher and lower than 800 ° C. in an inert gas atmosphere having an oxygen concentration of less than 5% after the preliminary heat treatment step. ,including. Since it is configured in this way, according to the method for forming a resist underlayer film according to the present embodiment, it is possible to provide a resist underlayer film or the like having excellent performance such as etching resistance. If the etching resistance of the resist underlayer film is insufficient, for example, when etching a substrate such as an oxide film or a nitride film, transfer size fluctuation occurs due to insufficient mask resistance of the resist underlayer film. That is, if the resist underlayer film having excellent etching resistance can be formed, a pattern having a good shape can be formed. Therefore, according to the method for forming a resist underlayer film according to the present embodiment, it can be suitably used for pattern formation using a multilayer resist process of a semiconductor device in which the pattern is further miniaturized.
Hereinafter, the material for forming a resist underlayer film in the present embodiment will be described in more detail.

[Material for forming a resist underlayer film]
The material for forming a resist underlayer film in the present embodiment is selected from the group consisting of aromatic compounds or resins thereof, that is, has at least one aromatic ring unit.

(Aromatic compound)
The aromatic compound in the present embodiment is not particularly limited as long as it has an aromatic ring and can be applied to a material for forming a resist underlayer film. Hereinafter, the aromatic compound in this embodiment will be described in detail.

（式（１Ａ）中、Ｘは酸素原子、硫黄原子、単結合又は無架橋であり、Ｒ^aは炭素数１～４０の２ｎ価の基又は単結合であり、Ｒ^bは各々独立して、置換基を有していてもよい炭素数１～４０のアルキル基、置換基を有していてもよい炭素数６～４０のアリール基、置換基を有していてもよい炭素数２～４０のアルケニル基、置換基を有していてもよい炭素数２～４０のアルキニル基、置換基を有していてもよい炭素数１～４０のアルコキシ基、ハロゲン原子、チオール基又は水酸基であり、ｍは各々独立して０～９の整数であり、ｎは１～４の整数であり、ｐは各々独立して０～２の整数である。ここで、Ｒ^bの少なくとも１つは水酸基及びチオール基から選ばれる１種を含む基であり、すべてのｍが同時に０となることはない。） (Compound represented by the formula (1A))
The aromatic compound in this embodiment is preferably a compound represented by the following formula (1A).

(In the formula (1A), X is an oxygen atom, a sulfur atom, a single bond or no cross-linking, R ^a is a 2n-valent group or a single bond having 1 to 40 carbon atoms, and R ^b is independent of each other. An alkyl group having 1 to 40 carbon atoms which may have a substituent, an aryl group having 6 to 40 carbon atoms which may have a substituent, and 2 to 40 carbon atoms which may have a substituent. An alkenyl group, an alkynyl group having 2 to 40 carbon atoms which may have a substituent, an alkoxy group having 1 to 40 carbon atoms which may have a substituent, a halogen atom, a thiol group or a hydroxyl group. m is an independently integer of 0 to 9, n is an integer of 1 to 4, and p is an independently of an integer of 0 to 2. where at least one of R ^b is a hydroxyl group and It is a group containing one selected from thiol groups, and not all m becomes 0 at the same time.)

Unless otherwise defined in the specification, "substitution" means that one or more hydrogen atoms in a functional group are substituted with a substituent. The "substituent" is not particularly limited, but is, for example, a halogen atom, a hydroxyl group, a carboxyl group, a cyano group, a nitro group, a thiol group, a heterocyclic group, an alkyl group having 1 to 30 carbon atoms, and 6 to 20 carbon atoms. Examples thereof include an aryl group, an alkoxyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, an acyl group having 1 to 30 carbon atoms, and an amino group having 0 to 30 carbon atoms. Be done.
Further, the "alkyl group" includes a linear aliphatic hydrocarbon group, a branched aliphatic hydrocarbon group, and a cyclic aliphatic hydrocarbon group unless otherwise defined.

In formula (1A), X indicates an oxygen atom, a sulfur atom, a single bond or no crosslink. In this embodiment, X is preferably an oxygen atom or no crosslink.
Ra is ^a 2n-valent group or a single bond having 1 to 40 carbon atoms. The 2n-valent group having 1 to 40 carbon atoms is, for example, an alkylene group having 1 to 40 carbon atoms when n = 1, an alkanetetrayl group having 1 to 40 carbon atoms when n = 2, and n = 3 When, it indicates an alkanehexayl group having 2 to 40 carbon atoms, and when n = 4, it indicates an alkaneoctayl group having 3 to 40 carbon atoms. Examples of the 2n-valent group include a group in which a 2n + 1-valent hydrocarbon group is bonded to a linear hydrocarbon group, a branched hydrocarbon group, or an alicyclic hydrocarbon group. Here, as for the alicyclic hydrocarbon group, the Aribashi alicyclic hydrocarbon group is also included.
Examples of the 2n + 1-valent hydrocarbon group include, but are not limited to, a trivalent methine group and an ethine group.
Further, the 2n-valent hydrocarbon group may have a double bond, a heteroatom and / or an aryl group having 6 to 39 carbon atoms. In addition, R ¹ may contain a group derived from a compound having a fluorene skeleton such as fluorene and benzofluorene.
Further, the 2n-valent group may contain a halogen group, a nitro group, an amino group, a hydroxyl group, an alkoxy group, a thiol group or an aromatic group having 6 to 40 carbon atoms. Further, the 2n-valent group may contain an ether bond, a ketone bond, an ester bond or a double bond.
The substituent which can be contained in the 2n-valent group and is not particularly limited as a linear hydrocarbon group and a branched hydrocarbon group, for example, an unsubstituted methyl group, an ethyl group and an n-propyl group. , I-propyl group, n-butyl group, i-butyl group, t-butyl group, n-pentyl group, n-hexyl group, n-dodecyl group, barrel group and the like.
The substituent which can be contained in the 2n-valent group and is not particularly limited as an alicyclic hydrocarbon group and an aromatic group having 6 to 39 carbon atoms is, for example, an unsubstituted phenyl group, a naphthalene group and a biphenyl. Group, anthracyl group, pyrenyl group, cyclohexyl group, cyclododecyl group, dicyclopentyl group, tricyclodecyl group, adamantyl group, phenylene group, naphthalenediyl group, biphenyldiyl group, anthracendiyl group, pyrenedyl group, cyclohexanediyl group, cyclo Dodecandyl group, dicyclopentanediyl group, tricyclodecandyl group, adamantandiyl group, benzenetriyl group, naphthalentryyl group, biphenyltriyl group, anthracentlyyl group, pyrentryyl group, cyclohexanetriyl group, cyclododecane Triyl group, dicyclopentanetriyl group, tricyclodecantryyl group, adamantantriyl group, benzenetetrayl group, naphthalenetetrayl group, biphenyltetrayl group, anthracentetrayl group, pyrenetetrayl group, cyclohexanetetra Examples thereof include an yl group, a cyclododecanetetrayl group, a dicyclopentanetetrayl group, a tricyclodecanetetrayl group, an adamantantetrayl group and the like.
Each of R ^b independently has an alkyl group having 1 to 40 carbon atoms which may have a substituent, an aryl group having 6 to 40 carbon atoms which may have a substituent, and a substituent. It may be an alkenyl group having 2 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms which may have a substituent, a halogen atom, a thiol group or a hydroxyl group. Here, the alkyl group may be linear, branched or cyclic.
Here, at least one of R ^b is a group containing one selected from a hydroxyl group and a thiol group.
The alkyl group having 1 to 40 carbon atoms is not limited to the following, but for example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a t-butyl group, and the like. Examples thereof include an n-pentyl group, an n-hexyl group, an n-dodecyl group and a barrel group.
Examples of the aryl group having 6 to 40 carbon atoms include, but are not limited to, a phenyl group, a naphthalene group, a biphenyl group, an anthracyl group, a pyrenyl group, a perylene group and the like.
Examples of the alkenyl group having 2 to 40 carbon atoms include, but are not limited to, an ethynyl group, a propenyl group, a butynyl group, a pentynyl group and the like.
Examples of the alkynyl group having 2 to 40 carbon atoms include, but are not limited to, alkynyl groups having 2 to 40 carbon atoms. Examples thereof include an acetylene group and an ethynyl group.
The alkoxy group having 1 to 40 carbon atoms is not limited to the following, and examples thereof include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a pentoxy group.
Examples of the halogen atom include, but are not limited to, fluorine, chlorine, bromine, and iodine.
m is an integer of 0 to 9 independently. Here, not all m are 0 at the same time.
n is an integer of 1 to 4, and p is an integer of 0 to 2 independently.

（式（１）中、Ｘ、ｍ、ｎ及びｐは前記式（１Ａ）において説明したものと同義であり、Ｒ¹は前記式（１Ａ）におけるＲ^aと同義であり、Ｒ²は各々独立して、炭素数１～４０のアルキル基、炭素数６～４０のアリール基、炭素数２～４０のアルケニル基、炭素数１～４０のアルコキシ基、ハロゲン原子、チオール基又は水酸基であり、ここで、Ｒ²の少なくとも１つは水酸基又はチオール基であり、すべてのｍが同時に０となることはない。） In the present embodiment, from the viewpoint of ease of production, the compound represented by the formula (1A) is preferably the compound represented by the following formula (1).

(In the formula (1), X, m, n and p are synonymous with those described in the above formula (1A), R ¹ is synonymous with R ^a in the above formula (1A), and R ² is independent of each other. An alkyl group having 1 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a halogen atom, a thiol group or a hydroxyl group. At least one of R ² is a hydroxyl group or a thiol group, and not all m are zero at the same time.)

（式（１－１）中、Ｚは酸素原子又は硫黄原子であり、Ｒ¹、Ｒ²、ｍ、ｐ及びｎは前記式（１）において説明したものと同義である。ここで、Ｒ²の少なくとも１つは水酸基及びチオール基から選ばれる１種であり、すべてのｍが同時に０となることはない。） In the present embodiment, the compound represented by the formula (1) is preferably a compound represented by the following formula (1-1) from the viewpoint of heat resistance.

(In the formula (1-1), Z is an oxygen atom or a sulfur atom, and R ¹ , R ² , m, p and n are synonymous with those described in the above formula (1). Here, R ² is used. At least one of them is one selected from a hydroxyl group and a thiol group, and not all m becomes 0 at the same time.)

（式（１－２）中、Ｒ¹、Ｒ²、ｍ、ｐ及びｎは前記式（１）において説明したものと同義である。ここで、Ｒ²の少なくとも１つは水酸基又はチオール基であり、すべてのｍが同時に０となることはない。） Further, the compound represented by the above formula (1-1) is preferably a compound represented by the following formula (1-2) from the viewpoint of raw material supply.

(In the formula (1-2), R ¹ , R ² , m, p and n are synonymous with those described in the above formula (1). Here, at least one of R ² is a hydroxyl group or a thiol group. Yes, not all m's are 0 at the same time.)

（式（１－３）中、Ｒ¹、ｐ及びｎは、前記式（１）で説明したものと同義であり、Ｒ⁴は各々独立して、炭素数１～４０のアルキル基、炭素数６～４０のアリール基、炭素数２～４０のアルケニル基、炭素数２～４０のアルキニル基、炭素数１～４０のアルコキシ基、ハロゲン原子又はチオール基であり、ｍ⁴は、各々独立して０～８の整数であり、ｑは、各々独立して０～８の整数である。ここで、すべてのｑが同時に０となることはない。） Further, the compound represented by the formula (1-2) is preferably a compound represented by the following formula (1-3) from the viewpoint of thermosetting properties and dissolution stability.

(In the formula (1-3), R ¹ , p and n are synonymous with those described in the above formula (1), and R ⁴ is an alkyl group having 1 to 40 carbon atoms and the number of carbon atoms, respectively. It is an aryl group of 6 to 40, an alkenyl group having 2 to 40 carbon atoms, an alkynyl group having 2 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a halogen atom or a thiol group, and m ⁴ is independent of each other. It is an integer of 0 to 8, and q is an integer of 0 to 8 independently. Here, not all qs are 0 at the same time.)

（式（１－４）中、Ｒ¹、ｐ及びｎは上記式（１）で説明したものと同義であり、Ｒ⁴は上記式（１－３）で説明したものと同義であり、ｍ⁴′は、各々独立して０～７の整数である。） Further, the compound represented by the formula (1-3) is preferably a compound represented by the following formula (1-4) from the viewpoint of heat resistance and dissolution stability.

(In the formula (1-4), R ¹ , p and n are synonymous with those described in the above formula (1), and R ⁴ is synonymous with the one described in the above formula (1-3). ⁴ ′ is an integer of 0 to 7 independently.)

（上記式（１－５）中、Ｒ¹は前記式（１）で説明したものと同義であり、Ｒ⁴は前記式（１－３）で説明したものと同義であり、ｍ⁴′′は各々独立して、０～５の整数である。） Further, the compound represented by the formula (1-4) is preferably a compound represented by the following formula (1-5) from the viewpoint of raw material availability and ease of production.

(In the above formula (1-5), R ¹ is synonymous with the one described in the above formula (1), and R ⁴ is synonymous with the one described in the above formula (1-3), m ⁴ ″. Are independently integers from 0 to 5.)

（式（３）中、Ｒ¹は前記式（１Ａ）におけるＲ^aと同義であり、ｎ及びｐは前記式（１Ａ）において説明したものと同義であり、Ｒ⁵及びＲ⁶は各々独立して炭素数１～４０のアルキル基、炭素数６～４０のアリール基、炭素数２～４０のアルケニル基、炭素数１～４０のアルコキシ基、ハロゲン原子、チオール基又は水酸基であり、ｍ⁵は各々独立して０～８の整数であり、ｍ⁶は各々独立して０～９の整数である。ここで、Ｒ⁵及びＲ⁶から選ばれる少なくとも１つは水酸基及びチオール基から選ばれる１種であり、すべてのｍ⁵及びｍ⁶が同時に０となることはない。） Further, the compound represented by the formula (1A) is preferably a compound represented by the following formula (3) from the viewpoint of improving solubility.

(In the formula (3), R ¹ is synonymous with R ^a in the formula (1A), n and p are synonymous with those described in the formula (1A), and R ⁵ and R ⁶ are independent of each other. It is an alkyl group having 1 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a halogen atom, a thiol group or a hydroxyl group, and m ⁵ is Each is an independently integer from 0 to 8, and m ⁶ is an independent integer from 0 to 9. where at least one selected from R ⁵ and R ⁶ is selected from a hydroxyl group and a thiol group. It is a species, and not all m ⁵ and m ⁶ are 0 at the same time.)

（式（３－１）中、Ｒ¹、Ｒ⁵、Ｒ⁶及びｎは、前記式（３）において説明したものと同義であり、ｍ^5'は各々独立して０～４の整数であり、ｍ^6'は各々独立して０～５の整数である。ここで、Ｒ⁵及びＲ⁶から選ばれる少なくとも１つは水酸基及びチオール基から選ばれる１種であり、すべてのｍ^5'及びｍ^6'が同時に０となることはない。） The compound represented by the formula (3) is preferably a compound represented by the following formula (3-1) from the viewpoint of availability of raw materials.

(In Eq. (3-1), R ¹ , R ⁵ , R ⁶ and n are synonymous with those described in Eq. (3), and m ^5'is an integer of 0 to 4 independently. , M ^6'are independently integers from 0 to 5. where at least one selected from R ⁵ and R ⁶ is one selected from hydroxyl and thiol groups, all m ^5'and. m ^6'cannot be 0 at the same time.)

（式（３－２）中、Ｒ¹は前記式（３）で説明したものと同義であり、Ｒ⁷及びＲ⁸は各々独立して炭素数１～４０のアルキル基、炭素数６～４０のアリール基、炭素数２～４０のアルケニル基、炭素数２～４０のアルキニル基、炭素数１～４０のアルコキシ基、ハロゲン原子、チオール基又は水酸基であり、ｍ⁷及びｍ⁸は各々独立して０～７の整数である。） The compound represented by the formula (3-1) is preferably a compound represented by the following formula (3-2) from the viewpoint of raw material availability and ease of production.

(In the formula (3-2), R ¹ has the same meaning as that described in the above formula (3), and R ⁷ and R ⁸ are independently alkyl groups having 1 to 40 carbon atoms and 6 to 40 carbon atoms, respectively. Aryl group, alkenyl group having 2 to 40 carbon atoms, alkynyl group having 2 to 40 carbon atoms, alkoxy group having 1 to 40 carbon atoms, halogen atom, thiol group or hydroxyl group, and m ⁷ and m ⁸ are independent of each other. It is an integer from 0 to 7.)

Specific examples of the compound represented by the formula (1) are illustrated below, but are not limited to those listed here.

In the above formula, R ² and X have the same meaning as those described in the above formula (1). m'is an integer from 0 to 7. Here, at least one of R ² is one selected from a hydroxyl group and a thiol group, and not all m'are set to 0 at the same time.

In the above formula, R ² and X have the same meaning as those described in the above formula (1).
m'is an integer from 0 to 7. m'' is an integer from 0 to 5. Here, at least one of R ² is one selected from a hydroxyl group and a thiol group, and m ′ and m ″ do not become 0 at the same time.

In the above equation, R ² , X and m'have the same meaning as described above. Here, at least one of R ² is one selected from a hydroxyl group and a thiol group, and not all m'are set to 0 at the same time.

In the above formula, R ² and X have the same meaning as those described in the above formula (1). m'is an integer from 0 to 7. m'' is an integer from 0 to 5. Here, at least one of R ² is one selected from a hydroxyl group and a thiol group, and m ′ and m ″ do not become 0 at the same time.

In the above formula, R ² and X have the same meaning as those described in the above formula (1). m'is an integer from 0 to 7. Here, at least one of R ² is one selected from a hydroxyl group and a thiol group, and not all m'are set to 0 at the same time.

In the above formula, R ² and X have the same meaning as those described in the above formula (1). m'is an integer from 0 to 7. m'' is an integer from 0 to 5. Here, at least one of R ² is one selected from a hydroxyl group and a thiol group, and m ′ and m ″ do not become 0 at the same time.

In the above formula, R ² and X have the same meaning as those described in the above formula (1). m'is an integer from 0 to 7. Here, at least one of R ² is one selected from a hydroxyl group and a thiol group, and not all m'are set to 0 at the same time.

In the above formula, R ² and X have the same meaning as those described in the above formula (1). m'is an integer from 0 to 7. m'' is an integer from 0 to 5. Here, at least one of R ² is one selected from a hydroxyl group and a thiol group, and m ′ and m ″ do not become 0 at the same time.

Specific examples of the compound represented by the above formula (3) are shown below, but are not limited to those listed here.

Among the compounds, R ⁵ and R ⁶ have the same meaning as those described in the above formula (3).
m ¹¹ is an integer of 0 to 6, and m ¹² is an integer of 0 to 7.
Here, at least one selected from R ⁵ and R ⁶ is one selected from a hydroxyl group and a thiol group, and all m ¹¹ and m ¹² do not become 0 at the same time.

Among the compounds, R ⁵ and R ⁶ have the same meaning as those described in the above formula (3).
m ^5'is an integer of 0 to 4 independently, and m ^6'is an integer of 0 to 5 independently.
Here, at least one selected from R ⁵ and R ⁶ is one selected from a hydroxyl group and a thiol group, and not all m ^5'and m ^6'are set to 0 at the same time.

Among the compounds, R ⁵ and R ⁶ have the same meaning as those described by the above formula (3). m ¹¹ is an integer of 0 to 6, and m ¹² is an integer of 0 to 7.
Here, at least one selected from R ¹¹ and R ¹² is one selected from a hydroxyl group and a thiol group, and not all m ¹¹ and m ¹² become 0 at the same time.

Among the compounds, R ⁵ and R ⁶ have the same meaning as those described in the above formula (1).
m ^5'is an integer of 0 to 4 independently, and m ^6'is an integer of 0 to 5 independently.
Here, at least one selected from R ⁵ and R ⁶ is one selected from a hydroxyl group and a thiol group, and not all m ^5'and m ^6'are set to 0 at the same time.

(Method for preparing the compound represented by the formula (1A))
The compound represented by the formula (1A) in the present embodiment can be appropriately synthesized by applying a known method, and the synthesis method is not particularly limited. The compound can be produced, for example, by the methods described in International Publication No. 2013/024779 and International Publication No. 2015/137486. The document describes a method for reacting naphthols, biphenols and the like with aldehydes and ketones under an acid catalyst.

(resin)
The resin in the present embodiment is not particularly limited as long as it is a resin derived from the aromatic compound in the present embodiment. Hereinafter, the resin in this embodiment will be described in detail.

（式（２Ａ）中、Ｘ、Ｒ^a、Ｒ^b、ｎ及びｐは、前記式（１Ａ）において説明したものと同義であり、Ｒ^cは単結合又は炭素数１～４０のアルキレン基であり、ｍ²は各々独立して０～８の整数である。ここで、Ｒ^bのうち、少なくとも１つは水酸基及びチオール基から選ばれる１種以上を含む基であり、すべてのｍ²が同時に０となることはない。） (Resin having a structure represented by the formula (2A))
The resin in this embodiment is preferably a resin having a structure represented by the following formula (2A).

(In the formula (2A), X, R ^a , R ^b , n and p are synonymous with those described in the above formula (1A), and R ^c is a single bond or an alkylene group having 1 to 40 carbon atoms. , M ² are independently integers from 0 to 8. Here, at least one of R ^b is a group containing at least one selected from a hydroxyl group and a thiol group, and all m ² are simultaneously. It will never be 0.)

（式（２）中、Ｘ、Ｒ¹、Ｒ²、ｎ及びｐは前記式（１）において説明したものと同義であり、Ｒ³は前記式（２Ａ）におけるＲ^cと同義であり、ｍ²は前記式（２Ａ）において説明したものと同義である。ここで、Ｒ²の少なくとも１つは水酸基及びチオール基から選ばれる１種であり、すべてのｍ²が同時に０となることはない。） The resin having the structure represented by the formula (2A) is preferably a resin having the structure represented by the following formula (2) from the viewpoint of ease of production.

(In the formula (2), X, R ¹ , R ² , n and p are synonymous with those described in the above formula (1), R ³ is synonymous with R ^c in the above formula (2A), and m. ² is synonymous with that described in the above formula (2A). Here, at least one of R ² is one selected from a hydroxyl group and a thiol group, and all m ² are not 0 at the same time. .)

The resin having the structure represented by the formula (2) is preferably a resin having the structure represented by the following formula (2-1) from the viewpoint of improving heat resistance.

In the above formula (2-1), Z has the same meaning as that described in the above formula (1-1), and indicates that it is an oxygen atom or a sulfur atom.
R ¹ , R ² , R ³ , m ² , p and n are synonymous with those described in the above equation (2). Here, at least one of R ² is one selected from a hydroxyl group and a thiol group, and not all m ² become 0 at the same time.

In the present embodiment, in the resin having the structure represented by the formula (2) or (2-1), R ³ is a single bond, and the aromatic rings are directly bonded to each other by the R ³ . Is preferable. Such a resin having a structure in which aromatic rings are directly connected by a direct bond is also referred to as a "polycyclic polyphenol resin" in the present specification. That is, the resin having the structure represented by the formula (2) or (2-1) is preferably a polycyclic polyphenol resin.

（式（４）中、Ｒ¹、ｐ及びｎは、上記式（２Ａ）で説明したものと同義であり、Ｒ⁵及びＲ⁶は各々独立して炭素数１～４０のアルキル基、炭素数６～４０のアリール基、炭素数２～４０のアルケニル基、炭素数１～４０のアルコキシ基、ハロゲン原子、チオール基又は水酸基であり、ｍ⁵は各々独立して０～８の整数であり、ｍ⁶は各々独立して０～９の整数である。ここで、Ｒ⁵及びＲ⁶から選ばれる少なくとも１つは水酸基及びチオール基から選ばれる１種であり、すべてのｍ⁵及びｍ⁶が同時に０となることはない。Ｒ³は前記式（２Ａ）におけるＲ^cと同義である。） Further, the resin having the structure represented by the above formula (2A) preferably has the structure represented by the following formula (4) from the viewpoint of dissolution stability.

(In the formula (4), R ¹ , p and n are synonymous with those described in the above formula (2A), and R ⁵ and R ⁶ are independently alkyl groups having 1 to 40 carbon atoms and carbon atoms, respectively. It is an aryl group of 6 to 40, an alkenyl group having 2 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a halogen atom, a thiol group or a hydroxyl group, and m ⁵ is an independently integer of 0 to 8. m ⁶ is an independently integer from 0 to 9. Here, at least one selected from R ⁵ and R ⁶ is one selected from a hydroxyl group and a thiol group, and all m ⁵ and m ⁶ are selected. It does not become 0 at the same time. R ³ is synonymous with R ^c in the above equation (2A).)

In the present embodiment, in the resin having the structure represented by the formula (4), it is preferable that R ³ is a single bond and the aromatic rings are directly bonded to each other by the R ³ . That is, the resin having the structure represented by the formula (4) is preferably a polycyclic polyphenol resin.

[Method for preparing a resin having a structure represented by the formula (2A)]
The resin having the structure represented by the formula (2A) used in the present embodiment can be appropriately synthesized by applying a known method, and the synthesis method is not particularly limited. The resin can be produced, for example, by the methods described in International Publication No. 2013/024779 and International Publication No. 2015/137486. The document describes a method for reacting a compound obtained by reacting naphthols, biphenols and the like with aldehydes and ketones under an acid catalyst with a crosslinkable compound to form an oligomer or a polymer. Is described.

In the present embodiment, the formula (1A), the formula (2A), the formula (1), the formula (1-1), the formula (1-2), the formula (1-3), the formula (1-4), the formula ( 1-5), formula (3), formula (3-1), formula (3-2), formula (2), formula (2-1) and ^RA or R ¹ in formula (4) are aryl. It may be a 2n-valent group having 1 to 40 carbon atoms including a group, or a group having a fluorene skeleton.
In the present embodiment, the formula (1A), the formula (2A), the formula (1), the formula (1-1), the formula (1-2), the formula (1-3), the formula (1-4), the formula ( 1-5), the formula (3), the formula (3-1), the formula (3-2), the formula (2), the formula (2-1) and the ^RA or R ¹ in the formula (4) are R. ^A group represented by ^{A -} RB, wherein the ^RA is a methine group, and the RB may have a substituent and is an aryl group having 6 to 30 carbon atoms. preferable.
The above-mentioned aryl group having 6 to 30 carbon atoms is not limited to the following, but may be, for example, a group derived from a benzene ring, naphthalene, anthracene, naphthalene, pentacene, benzopyrene, chrysene, pyrene, triphenylene. , Corannulene, coronene, ovalene and the like may be a group derived from various known fused rings.
Examples of the group having a fluorene skeleton include 2n-valent groups derived from fluorene, benzofluorene, dibenzofluorene and the like.

（式（１Ｂ）中、Ａはベンゼン環又は縮合環を表す。さらに、Ｒ⁰は各々独立して、置換基を有していてもよい炭素数１～４０のアルキル基、置換基を有していてもよい炭素数６～４０のアリール基、置換基を有していてもよい炭素数２～４０のアルケニル基、置換基を有していてもよい炭素数２～４０のアルキニル基、置換基を有していてもよい炭素数１～４０のアルコキシ基、ハロゲン原子、チオール基又は水酸基であり、ここで、Ｒ⁰の少なくとも１つは水酸基であり、ｍは０～９の整数である。） [Polycyclic polyphenol resin having a repeating unit derived from an aromatic hydroxy compound represented by the formula (1B)]
The resin in the present embodiment is a polycyclic polyphenol resin having a repeating unit derived from an aromatic hydroxy compound represented by the formula (1B), and the repeating units are linked by a direct bond between the aromatic rings. It is also possible to use a polycyclic polyphenol resin.

(In the formula (1B), A represents a benzene ring or a condensed ring. Further, R ⁰ independently has an alkyl group having 1 to 40 carbon atoms and a substituent which may have a substituent. An aryl group having 6 to 40 carbon atoms which may be present, an alkenyl group having 2 to 40 carbon atoms which may have a substituent, an alkynyl group having 2 to 40 carbon atoms which may have a substituent, and a substituent. It is an alkoxy group, a halogen atom, a thiol group or a hydroxyl group having 1 to 40 carbon atoms which may have a group, where at least one of R ⁰ is a hydroxyl group and m is an integer of 0 to 9. .)

The A in the formula (1B) is not particularly limited, but may be, for example, a benzene ring, naphthalene, anthracene, naphthalene, pentacene, benzopyrene, chrysene, pyrene, triphenylene, corannulene, coronene and ovalene. It may be various known fused rings such as. In the present embodiment, it is preferable that A is various fused rings such as naphthalene, anthracene, naphthalene, pentacene, benzopyrene, chrysene, pyrene, triphenylene, corannulene, coronene and ovalene from the viewpoint of heat resistance. Further, it is preferable that A is naphthalene or anthracene because the n-value and k-value at a wavelength of 193 nm used in ArF exposure tend to be low and the pattern transferability tends to be excellent.
In addition to the above-mentioned aromatic hydrocarbon ring, the above-mentioned A includes heterocycles such as pyridine, pyrrole, pyridazine, thiophene, imidazole, furan, pyrazole, oxazole, triazole, thiazole, or benzo-condensed rings thereof.

（式（１Ｂ’）中、Ｒ⁰、ｍ及びｐは、それぞれ、式（１Ａ）におけるＲ^b、ｍ及びｐと同義である。また、式（１Ｂ’’）中、Ｒ⁰は式（１Ａ）におけるＲ^bと同義であり、ｍ⁰は０～４の整数であり、全てのｍ⁰が同時に０になることはない。） In the present embodiment, preferred examples of the aromatic hydroxy compound represented by the formula (1B) include aromatic hydroxy compounds represented by the following formulas (1B') and (1B'').

(In the formula (1B'), R ⁰ , m and p are synonymous with R ^b , m and p in the formula (1A), respectively. In the formula (1B''), R ⁰ is the formula (1A). ) Is synonymous with R ^b , m ⁰ is an integer from 0 to 4, and not all m ^0s become 0 at the same time.)

Specific examples of the aromatic hydroxy compound represented by the above formula (1B') are shown below, but are not limited to those listed here.

In the formula (B-1), n ⁰ is an integer of 0 to 4, and in the formula (B-2), n ⁰ is an integer of 0 to 6, and the formulas (B-3) to (B). In -4), n ⁰ is an integer from 0 to 8.

Among the aromatic hydroxy compounds represented by the formulas (B-1) to (B-4), those represented by (B-3) to (B-4) are preferable from the viewpoint of improving the etching resistance. Further, from the viewpoint of optical characteristics, those represented by (B-2) to (B-3) are preferable. Further, from the viewpoint of flatness, those represented by (B-1) to (B-2) and (B-4) are preferable, and those represented by (B-4) are more preferable.
From the viewpoint of heat resistance, it is preferable that any one carbon atom of the aromatic ring having a phenolic hydroxyl group participates in the direct bond between the aromatic rings.

Specific examples of the aromatic hydroxy compound represented by the above formula (1B ″) are shown below, but are not limited to those listed here.

（式（Ｂ－５）中、ｎ¹は０～８の整数である。） In addition to the above, an aromatic hydroxy compound represented by the following B-5 can also be used as a specific example of the formula (1B) from the viewpoint of further improving the etching resistance.

(In equation (B-5), n ¹ is an integer from 0 to 8.)

In the present embodiment, the aromatic hydroxy compound represented by the above formula (1B) can also be used as the aromatic compound in the present embodiment.

The resin in the present embodiment may further have a modified moiety derived from a cross-linking reactive compound. That is, the resin in the present embodiment having the above-mentioned structure may have a modified portion obtained by reaction with a compound having a cross-linking reactivity. Such modified resins also have excellent heat resistance and etching resistance, and can be used as coating agents for semiconductors, resist materials, and semiconductor underlayer film forming materials.

The cross-linking reactive compound is not limited to the following, and includes, for example, aldehydes, ketones, carboxylic acids, carboxylic acid halides, halogen-containing compounds, amino compounds, imino compounds, isocyanate compounds, and unsaturated hydrocarbon groups. Examples include compounds. These can be used alone or in combination of two as appropriate.

In the present embodiment, the cross-linking reactive compound is preferably an aldehyde or a ketone. In particular, it is preferably a polycyclic polyphenol resin obtained by polycondensing reaction of aldehydes or ketones with the resin in the present embodiment having the above-mentioned structure in the presence of a catalyst. For example, a novolak-type polyphenolic polyphenol resin can be obtained by further polycondensing with aldehydes or ketones corresponding to a desired structure under normal pressure and, if necessary, under pressure under a catalyst. can.

Examples of the aldehydes include methylbenzaldehyde, dimethylbenzaldehyde, trimethylbenzaldehyde, ethylbenzaldehyde, propylbenzaldehyde, butylbenzaldehyde, pentabenzaldehyde, butylmethylbenzaldehyde, hydroxybenzaldehyde, dihydroxybenzaldehyde, fluoromethylbenzaldehyde and the like. Not particularly limited. These can be used alone or in combination of two or more. Among these, it is preferable to use methylbenzaldehyde, dimethylbenzaldehyde, trimethylbenzaldehyde, ethylbenzaldehyde, propylbenzaldehyde, butylbenzaldehyde, pentabenzaldehyde, butylmethylbenzaldehyde and the like from the viewpoint of imparting high heat resistance.

Examples of the ketones include acetylmethylbenzene, acetyldimethylbenzene, acetyltrimethylbenzene, acetylethylbenzene, acetylpropylbenzene, acetylbutylbenzene, acetylpentabenzene, acetylbutylmethylbenzene, acetylhydroxybenzene, acetyldihydroxybenzene, and acetylfluororo. Examples thereof include methylbenzene, but the present invention is not particularly limited thereto. These can be used alone or in combination of two or more. Among these, it is preferable to use acetylmethylbenzene, acetyldimethylbenzene, acetyltrimethylbenzene, acetylethylbenzene, acetylpropylbenzene, acetylbutylbenzene, acetylpentabenzene, and acetylbutylmethylbenzene from the viewpoint of imparting high heat resistance.

The catalyst used in the reaction can be appropriately selected from known catalysts and is not particularly limited. As the catalyst, an acid catalyst or a base catalyst is preferably used.
Inorganic acids and organic acids are widely known as such acid catalysts. Specific examples of the above acid catalyst include inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromic acid and hydrofluoric acid; Organic acids such as acid, formic acid, p-toluenesulfonic acid, methanesulfonic acid, trifluoroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, naphthalenesulfonic acid, naphthalenedisulfonic acid; zinc chloride, aluminum chloride , Lewis acids such as iron chloride and boron trifluoride; solid acids such as silicate tung acid, phosphotung acid, silicate molybdic acid, phosphomolybdic acid and the like, but are not particularly limited thereto. Among these, organic acids and solid acids are preferable from the viewpoint of production, and hydrochloric acid or sulfuric acid is preferably used from the viewpoint of production such as easy availability and handling.
Examples of such base catalysts are pyridine and ethylenediamine as examples of amine-containing catalysts, and metal salts and particularly potassium or acetate are preferable as examples of non-amine basic catalysts, and suitable catalysts are limited. However, examples thereof include potassium acetate, potassium carbonate, potassium hydroxide, sodium acetate, sodium carbonate, sodium hydroxide and magnesium oxide.
All non-amine base catalysts in this embodiment are commercially available, for example, from EMScience or Aldrich.
As for the catalyst, one type can be used alone or two or more types can be used in combination. The amount of the catalyst used can be appropriately set according to the raw material to be used, the type of the catalyst to be used, the reaction conditions, and the like, and is not particularly limited, but is 0.001 to 100 mass with respect to 100 parts by mass of the reaction raw material. It is preferably a part.

A reaction solvent may be used in the reaction. The reaction solvent is not particularly limited as long as the reaction between the aldehydes or ketones used and the resin in the present embodiment proceeds, and can be appropriately selected from known ones and used, for example. Examples thereof include water, methanol, ethanol, propanol, butanol, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, or a mixed solvent thereof. As the solvent, one type can be used alone, or two or more types can be used in combination. The amount of these solvents used can be appropriately set according to the raw materials used, the type of acid catalyst used, reaction conditions, and the like. The amount of the solvent used is not particularly limited, but is preferably in the range of 0 to 2000 parts by mass with respect to 100 parts by mass of the reaction raw material. Further, the reaction temperature in the above reaction can be appropriately selected according to the reactivity of the reaction raw material. The reaction temperature is not particularly limited, but is usually preferably in the range of 10 to 200 ° C. The reaction method can be appropriately selected and used by a known method, and is not particularly limited, but is the method of collectively charging the resin, aldehydes or ketones, acid catalyst in the present embodiment, or the aldehydes or ketones. There is a method of dropping in the presence of an acid catalyst. After completion of the polycondensation reaction, isolation of the obtained compound can be carried out according to a conventional method and is not particularly limited. For example, in order to remove unreacted raw materials, acid catalysts, etc. existing in the system, a general method such as raising the temperature of the reaction kettle to 130 to 230 ° C. and removing volatile substances at about 1 to 50 mmHg is used. By taking it, the target compound can be obtained.

In the resin of the present embodiment, the number and ratio of each repeating unit are not particularly limited, but it is preferable to appropriately adjust the number and ratio in consideration of the intended use and the following molecular weight values.
Further, the polycyclic polyphenol resin in the present embodiment can be composed of only the above-mentioned specific repeating units such as the repeating unit (1A) and / or (1B), but does not impair the performance according to the application. The range may include other repeating units. Other repeating units include, for example, a repeating unit having an ether bond formed by condensation of phenolic hydroxyl groups, a repeating unit having a ketone structure, and the like. These other repeating units may also be directly bonded to the repeating units (1A) and / or (1B) at the aromatic rings.
For example, the molar ratio [Y / X] of the total amount (Y) of the repeating unit (1A) and / or (1B) to the total amount (X) of the polycyclic polyphenol resin in the present embodiment is 0.05 to 1.00. It can be preferably 0.45 to 1.00.
The mass average molecular weight of the resin in the present embodiment is not particularly limited, but is preferably in the range of 1000 to 100,000, more preferably 1000 to 15,000, and even more preferably 3200 to 12000.
The range of the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is not particularly limited because the ratio required depending on the application is different, but it is more uniform. Examples of those having a high molecular weight include those having a preferable molecular weight in the range of 3.0 or less, more preferable ones in the range of 1.05 or more and 3.0 or less, and particularly preferable ones in the range of 1. Those of 05 or more and less than 2.0 are mentioned, and those of 1.05 or more and less than 1.5 are more preferable from the viewpoint of heat resistance.

The binding order of the repeating units of the polycyclic polyphenol resin in the present embodiment in the resin is not particularly limited. For example, only one unit derived from the aromatic hydroxy compound represented by the formula (1A) or the formula (1B) described later may be contained as a repeating unit in an amount of two or more, or the formula (1A) or the formula. A plurality of units derived from the aromatic hydroxy compound represented by (1B) may be contained in an amount of 1 or more. The order may be either block copolymerization or random copolymerization.

The position where the repeating units in the polycyclic polyphenol resin in the present embodiment are directly bonded to each other is not particularly limited, and when the repeating unit is represented by the general formula (1A) or the formula (1B), it is not particularly limited. Any one carbon atom to which the phenolic hydroxyl group and other substituents are not bonded participates in the direct bond between the monomers.
In the polycyclic polyphenol resin of the present embodiment, "the repeating units are linked by direct bonds between the aromatic rings" means that, as an example, the repeating units (1A) in the polycyclic polyphenol resin are one of the repeating units. The carbon atom on the aromatic ring represented by the aryl structure in the parentheses in the formula of the unit (1A) and the carbon on the aromatic represented by the aryl structure in the parentheses in the other repeating unit (1A). An embodiment in which an atom is directly bonded by a single bond, that is, without interposing other atoms such as a carbon atom, an oxygen atom, and a sulfur atom can be mentioned.
In addition, the present embodiment may include the following aspects.
(1) In one repeating unit (1A), when either Ra or R ^b is an aryl group ⁽ including the case where R ^a is a 2n-valent group having an aryl group), the aromatic of the aryl group. An embodiment in which an atom on the ring and an atom on the aromatic ring represented by an aryl structure in parentheses in the formula of the other repeating unit (1A) are directly bonded by a single bond.
(2) In the repeating unit (1A) of one and the other, when either R ^a or R ^b is an aryl group (including the case where R ^a is a 2n-valent group having an aryl group), one and the other. An embodiment in which atoms on the aromatic ring of the aryl group represented by Ra and R ^b are directly bonded by a single bond between the repeating units (1A ⁾ of.
In this embodiment, in any of the above embodiments (1) and (2), from the viewpoint of heat resistance, the carbon atom of any one of the aromatic rings having a phenolic hydroxyl group is attached to the aromatic rings. It is preferable to be involved in direct binding.

[Composition]
The composition in the present embodiment is not particularly limited as long as it contains the above-mentioned material for forming a resist underlayer film, and may contain various other components. The composition in the present embodiment can contain, for example, the above-mentioned material for forming a resist underlayer film and a solvent described later, and the composition can contain various surfactants, various cross-linking agents, and various acid generations. It may further contain an agent, various stabilizers and the like.

(solvent)
As the solvent used in the composition of the present embodiment, a known solvent can be appropriately used as long as the above-mentioned material for forming a resist underlayer film is at least soluble.

Specific examples of the solvent are not particularly limited, and examples thereof include those described in International Publication No. 2013/024779.
Specific examples of the solvent used include, but are not limited to, ethyl ether, isopropyl ether, n-butyl ether, hexyl ether, 2-ethylhexyl ether, ethylene oxide, 1,2-propylene oxide, dioxolane, 4-methyldioxolane, and the like. Dioxane, dimethyl dioxane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol monobutyl ether ethylene glycol mono-n-hexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, ethylene Glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriglycol, tetraethylene glycol dibutyl ether, propylene glycol monomethyl ether (PGME) , Dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol monopropyl ether, tetrahydrofuran, ethers such as 2-methyltetra, methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, sec-butanol, t-butanol, n-pentanol, i-pentanol, 2-methylbutanol, sec-pentanol, t-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec- Hexanol, 2-ethylbutanol, sec-heptanol, heptanol-3, n-octanol, 2-ethylhexanol, sec-octanol, nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, sec-undecyl alcohol , Trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol, diacetone alcohol, cresol, etc. Monoalcohols, diethyl carbonate, Methyl acetate, ethyl acetate, γ-butyrolactone, γ-valerolactone, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl acetate, nonyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol acetate Monoethyl ether, propylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, glycol diacetate, methoxytriglycolacetate, ethyl propionate, n-butyl propionate, i-pentyl propionate , Methyl methoxypropionate, ethyl ethoxypropionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-pentyl lactate, diethyl malonate, dimethyl phthalate, diethyl phthalate Esters such as acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl isobutyl ketone, methyl-n-pentyl ketone, ethyl butyl ketone, methyl hexyl ketone, diisobutyl ketone, trimethylnonanone , Cyclohexanone, Methylcyclohexanone, 2,4-Pentandione, Acetonylacetone, Acetphenone, N-Methylpyrrolidone and other ketones, Ethylene glycol monoethyl ether acetate, Ethylene glycol monobutyl ether acetate, Propropylene glycol monomethyl ether acetate (PGMEA), Glycol ether acetates such as propylene glycol monoethyl ether acetate, N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropion Nitrogen compound solvents such as amide and N-methylpyrrolidone, aliphatic hydrocarbons such as n-hexane and n-heptane, aromatic hydrocarbons such as toluene and xylene, and halogenated hydrocarbons such as methylene chloride and chloroform. And so on.

Among these, ethyl acetate, butyl acetate, methyl isobutyrate ketone, propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), cyclopentanone, cyclohexanone, methyl hydroxyisobutyrate, and anisole are preferable. Each of these solvents can be used alone, or two or more of them can be mixed and used. It is preferable in terms of workability and ease of managing the amount of preparation.

As the above-mentioned solvent, one kind may be used alone, or two or more kinds may be used in combination.

The content of the solvent is not particularly limited, but is preferably 100 to 10,000 parts by mass with respect to 100 parts by mass of the resist underlayer film forming material in the present embodiment from the viewpoint of solubility and film formation. , 200 to 5,000 parts by mass, more preferably 200 to 1,000 parts by mass.

The content of the resist underlayer film forming material in the present embodiment is preferably 1 to 100% by mass, preferably 10 to 100% by mass, in the composition from the viewpoint of coatability and quality stability. It is more preferably 50 to 100% by mass, and particularly preferably 100% by mass.

When the composition in the present embodiment contains a solvent, the content of the resist underlayer film forming material in the present embodiment is not particularly limited, but is 1 to 33 parts by mass with respect to 100 parts by mass of the total amount containing the solvent. It is preferably 2 to 25 parts by mass, more preferably 3 to 20 parts by mass.

The composition in the present embodiment can be applied to a wet process and has excellent heat resistance and etching resistance. Further, since the composition in the present embodiment contains the material for forming the resist underlayer film in the present embodiment, deterioration of the film during high temperature baking is suppressed by carrying out the preliminary heat treatment step and the heat treatment step described later, and oxygen plasma. It is possible to form an underlayer film having excellent etching resistance to etching and the like. Further, since the composition in the present embodiment tends to have excellent adhesion to the resist layer, an excellent resist pattern tends to be obtained. The composition in the present embodiment may contain a previously known underlayer film forming material for lithography and the like as long as the desired effect of the present embodiment is not impaired.

(Crosslinking agent)
The composition in the present embodiment may contain a cross-linking agent, if necessary, from the viewpoint of suppressing intermixing and the like. The cross-linking agent that can be used in the present embodiment is not particularly limited, and for example, those described in International Publication No. 2013/024778, International Publication No. 2013/024779, and International Publication No. 2018/016614 may be used. can. In this embodiment, the cross-linking agent may be used alone or in combination of two or more.

Specific examples of the cross-linking agent that can be used in this embodiment include a phenol compound (excluding the polycyclic polyphenol resin in this embodiment), an epoxy compound, a cyanate compound, an amino compound, a benzoxazine compound, an acrylate compound, and a melamine compound. , Guanamin compound, glycol uryl compound, urea compound, isocyanate compound, azido compound and the like, but are not particularly limited thereto. These cross-linking agents may be used alone or in combination of two or more. Among these, a benzoxazine compound, an epoxy compound or a cyanate compound is preferable, and a benzoxazine compound is more preferable from the viewpoint of improving etching resistance. Further, a melamine compound and a urea compound are more preferable because they have good reactivity. Examples of the melamine compound include a compound represented by the formula (a) (Nicarac MW-100LM (trade name), manufactured by Sanwa Chemical Co., Ltd.) and a compound represented by the formula (b) (Nicarac MX270 (commodity). Name), manufactured by Sanwa Chemical Co., Ltd.).

As the phenol compound, known compounds can be used, and the phenol compound is not particularly limited, but an aralkyl-type phenol resin is preferable from the viewpoint of heat resistance and solubility.

As the epoxy compound, known ones can be used and are not particularly limited, but are preferably in a solid state at room temperature such as phenol aralkyl resins and epoxy resins obtained from biphenyl aralkyl resins from the viewpoint of heat resistance and solubility. It is an epoxy resin.

The cyanate compound is not particularly limited as long as it is a compound having two or more cyanate groups in one molecule, and known compounds can be used. In the present embodiment, a preferable cyanate compound has a structure in which the hydroxyl group of a compound having two or more hydroxyl groups in one molecule is replaced with a cyanate group. Further, the cyanate compound preferably has an aromatic group, and a compound having a structure in which the cyanate group is directly linked to the aromatic group can be preferably used. Such cyanate compounds are not particularly limited, but are, for example, bisphenol A, bisphenol F, bisphenol M, bisphenol P, bisphenol E, phenol novolak resin, cresol novolak resin, dicyclopentadiene novolak resin, tetramethylbisphenol F, bisphenol. A novolak resin, brominated bisphenol A, brominated phenol novolak resin, trifunctional phenol, tetrafunctional phenol, naphthalene type phenol, biphenyl type phenol, phenol aralkyl resin, biphenyl aralkyl resin, naphthol aralkyl resin, dicyclopentadiene aralkyl resin, fat Examples thereof include those having a structure in which hydroxyl groups such as cyclic phenol and phosphorus-containing phenol are substituted with cyanate groups. Further, the cyanate compound may be in any form of a monomer, an oligomer or a resin.

As the amino compound, known compounds can be used, and the present invention is not particularly limited, but 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, and 4,4'-diaminodiphenyl ether have heat resistance and availability of raw materials. Preferred from the point of view.

As the benzoxazine compound, known compounds can be used, and the compound is not particularly limited, but Pd-type benzoxazine obtained from bifunctional diamines and monofunctional phenols is preferable from the viewpoint of heat resistance.

As the melamine compound, known compounds can be used, and the raw material is not particularly limited, but a compound in which 1 to 6 methylol groups of hexamethylol melamine, hexamethoxymethyl melamine, and hexamethylol melamine are methoxymethylated or a mixture thereof can be obtained as a raw material. It is preferable from the viewpoint of sex.

As the guanamine compound, known compounds can be used, and the compound is not particularly limited, but a compound in which 1 to 4 methylol groups of tetramethylol guanamine, tetramethoxymethyl guanamine, and tetramethylol guanamine are methoxymethylated or a mixture thereof is heat resistant. It is preferable from the viewpoint of.

As the glycol uryl compound, known compounds can be used, and the present invention is not particularly limited, but tetramethylol glycol urilu and tetramethoxyglycol uryl are preferable from the viewpoint of heat resistance and etching resistance.

As the urea compound, known compounds can be used, and the present invention is not particularly limited, but tetramethylurea and tetramethoxymethylurea are preferable from the viewpoint of heat resistance.

Further, in the present embodiment, a cross-linking agent having at least one allyl group may be used from the viewpoint of improving the cross-linking property. Among them, 2,2-bis (3-allyl-4-hydroxyphenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (3-allyl-4-hydroxyphenyl) propane , Bis (3-allyl-4-hydroxyphenyl) sulfone, bis (3-allyl-4-hydroxyphenyl) sulfide, bis (3-allyl-4-hydroxyphenyl) ether and other allylphenols are preferable.

In the composition of the present embodiment, the content of the cross-linking agent is not particularly limited, but is preferably 5 to 50 parts by mass, more preferably 10 parts by mass with respect to 100 parts by mass of the polycyclic polyphenol resin in the present embodiment. ~ 40 parts by mass. By setting the above-mentioned preferable range, the occurrence of the mixing phenomenon with the resist layer tends to be suppressed, the antireflection effect is enhanced, and the film forming property after crosslinking tends to be enhanced.

(Crosslink accelerator)
If necessary, a cross-linking accelerator for promoting a cross-linking and curing reaction can be used for the composition in the present embodiment.

The cross-linking accelerator is not particularly limited as long as it promotes the cross-linking and curing reaction, and examples thereof include amines, imidazoles, organic phosphines, and Lewis acids. These cross-linking accelerators can be used alone or in combination of two or more. Among these, imidazoles or organic phosphines are preferable, and imidazoles are more preferable from the viewpoint of lowering the crosslinking temperature.

As the cross-linking accelerator, known ones can be used, and the cross-linking accelerator is not particularly limited, and examples thereof include those described in International Publication No. 2018/016614. From the viewpoint of heat resistance and curing promotion, 2-methylimidazole, 2-phenylimidazole, and 2-ethyl-4-methylimidazole are particularly preferable.

The content of the cross-linking accelerator is usually preferably 0.1 to 10 parts by mass, more preferably controlled, when the total mass of the composition is 100 parts by mass and 100 parts by mass. From the viewpoint of ease and economy, it is 0.1 to 5 parts by mass, more preferably 0.1 to 3 parts by mass.

(Radical polymerization initiator)
A radical polymerization initiator can be added to the composition of the present embodiment, if necessary. The radical polymerization initiator may be a photopolymerization initiator that initiates radical polymerization by light, or a thermal polymerization initiator that initiates radical polymerization by heat. The radical polymerization initiator may be, for example, at least one selected from the group consisting of a ketone-based photopolymerization initiator, an organic peroxide-based polymerization initiator, and an azo-based polymerization initiator.

The radical polymerization initiator is not particularly limited, and conventionally used ones can be appropriately adopted. For example, those described in International Publication No. 2018/016614 can be mentioned. Of these, dicumyl peroxide, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, and t-butylcumyl peroxide are particularly preferable from the viewpoint of raw material availability and storage stability. ..

As the radical polymerization initiator used in the present embodiment, one of these may be used alone, two or more thereof may be used in combination, or another known polymerization initiator may be further used in combination. ..

(Acid generator)
The composition in the present embodiment may contain an acid generator, if necessary, from the viewpoint of further promoting the cross-linking reaction by heat. As the acid generator, those that generate acid by thermal decomposition, those that generate acid by light irradiation, and the like are known, but any of them can be used.

The acid generator is not particularly limited, but for example, the acid generator described in International Publication No. 2013/024779 can be used. In this embodiment, the acid generator can be used alone or in combination of two or more.

In the composition of the present embodiment, the content of the acid generator is not particularly limited, but is preferably 0.1 to 50 parts by mass with respect to 100 parts by mass of the polycyclic polyphenol resin in the present embodiment. It is preferably 0.5 to 40 parts by mass. By setting the above-mentioned preferable range, the amount of acid generated tends to increase and the crosslinking reaction tends to be enhanced, and the occurrence of the mixing phenomenon with the resist layer tends to be suppressed.

(Basic compound)
Further, the composition in the present embodiment may contain a basic compound from the viewpoint of improving storage stability and the like.

The basic compound acts as a quencher for the acid to prevent the acid generated in a smaller amount than the acid generator from advancing the cross-linking reaction. Examples of such basic compounds include primary, secondary or tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, and nitrogen-containing compounds having a carboxy group. Examples thereof include a nitrogen-containing compound having a sulfonyl group, a nitrogen-containing compound having a hydroxyl group, a nitrogen-containing compound having a hydroxyphenyl group, an alcoholic nitrogen-containing compound, an amide derivative, an imide derivative and the like, but the present invention is not particularly limited thereto.

The basic compound used in the present embodiment is not particularly limited, but for example, the compound described in International Publication No. 2013/024779 can be used. In this embodiment, the basic compound may be used alone or in combination of two or more.

In the composition of the present embodiment, the content of the basic compound is not particularly limited, but is preferably 0.001 to 2 parts by mass with respect to 100 parts by mass of the polyphenol resin in the present embodiment. It is preferably 0.01 to 1 part by mass. By setting the above-mentioned preferable range, the storage stability tends to be enhanced without excessively impairing the crosslinking reaction.

(Other additives)
Further, the composition in the present embodiment may contain other resins and / or compounds for the purpose of imparting thermosetting property and controlling the absorbance. Examples of such other resins and / or compounds include naphthalene resin, xylene resin, naphthalene-modified resin, phenol-modified resin of naphthalene resin, polyhydroxystyrene, dicyclopentadiene resin, (meth) acrylate, dimethacrylate, and trimethacrylate. , Tetramethacrylate, vinylnaphthalene, naphthalene rings such as polyacenaphthalene, biphenyl rings such as phenanthrenquinone and fluorene, resins containing heterocycles having heteroatoms such as thiophene and indene, and resins not containing aromatic rings; Examples thereof include resins or compounds containing an alicyclic structure such as resins, cyclodextrines, adamantan (poly) all, tricyclodecane (poly) all and derivatives thereof, but are not particularly limited thereto. Further, the composition of the present embodiment may contain a known additive. Examples of the known additives include, but are not limited to, ultraviolet absorbers, surfactants, colorants, nonionic surfactants, and the like.

[Applying process]
In the coating step carried out in the method for forming a resist underlayer film according to the present embodiment, a composition containing a resist underlayer film forming material selected from the group consisting of the above-mentioned aromatic compounds or resins thereof is applied onto a substrate. ..

The substrate that can be used in this embodiment is not particularly limited, but for example, a semiconductor substrate such as silicon oxide film, silicon nitride film, or silicon on which a silicon oxide nitride film is formed, a silicon nitride substrate, a quartz substrate, or a glass substrate (non-alkali). Includes glass, low-alkali glass and crystallized glass), glass substrates on which an ITO film is formed, and the like. The procedure for coating in the coating step is not particularly limited, and for example, the composition according to the present embodiment can be coated on the substrate described above by an appropriate coating method such as a spinner or a coater.

[Preliminary heat treatment process]
In the preliminary heat treatment step carried out in the method for forming the resist underlayer film according to the present embodiment, the composition coated as described above is heated at 50 ° C. or higher and 300 ° C. or lower. That is, by heating the substrate coated with the composition in the present embodiment at a predetermined temperature, a curing reaction occurs and a resist underlayer film precursor is formed.

The heating means in the preheat treatment step is not particularly limited, but for example, a hot plate or the like can be used. The heating conditions at that time are preferably 50 ° C. or higher and 300 ° C. or lower, preferably 50 ° C. or higher and 250 ° C. or lower, and more preferably 50 ° C. or higher and 200 ° C. or lower. In the preheat treatment step, by heating at a temperature of 300 ° C. or lower, it is possible to improve the heat resistance of the film due to curing while suppressing excessive oxidation of the resist underlayer film forming material even in an air atmosphere. It becomes. Therefore, it is possible to promote carbonization by dehydration and dehydrogenation while avoiding oxidation and decomposition of the film in the subsequent heat treatment step, so that a resist underlayer film having a high carbon concentration and excellent etching resistance can be formed. can.

The heating time in the preheat treatment step is preferably 15 seconds or longer, more preferably 30 seconds or longer, and even more preferably 45 seconds or longer. The heating time is preferably 20 minutes or less, more preferably 1,200 seconds or less, further preferably 600 seconds or less, and even more preferably 300 seconds.

The atmosphere in the preheat treatment step is preferably an inert gas atmosphere in which nitrogen, argon or a mixture thereof is present. Here, the oxygen concentration in the preheat treatment step is preferably less than 20%, more preferably less than 5%. In the present specification, the oxygen concentration is specified as a volume basis.

[Heat treatment process]
The heat treatment step carried out in the method for forming the resist underlayer film according to the present embodiment is carried out after the above-mentioned preliminary heat treatment step. In the heat treatment step in the present embodiment, heating is performed at a temperature of 400 ° C. or higher and lower than 800 ° C. in an inert gas atmosphere having an oxygen concentration of less than 5%.
The heat treatment step is performed in a low oxygen concentration atmosphere with an oxygen concentration of less than 5.0%, and the heating temperature is set to such a temperature that the underlying film does not thermally decompose, so that the film is suppressed from excessive oxidation. The curing reaction can be advanced, the thermal decomposition temperature can be improved, and the upper limit of the baking temperature can be set higher than that in the case of baking in the air. When the heating temperature is less than 400 ° C. and 800 ° C. or higher, the characteristics required for the resist underlayer film may not be exhibited. Further, in the temperature range in which the lower film does not thermally decompose, the higher the bake temperature, the higher the density of the film formed.
From the above viewpoint, the heating temperature in the heat treatment step is preferably 450 ° C. or higher, more preferably 500 ° C. or higher, still more preferably 550 ° C. or higher. The heating temperature is preferably 650 ° C or lower, more preferably 600 ° C or lower.

The heating time in the heat treatment step is preferably 15 seconds or more and 20 minutes or less. The heating time is more preferably 30 seconds or longer, and even more preferably 45 seconds or longer. The heating time is more preferably 1,200 seconds or less, further preferably 600 seconds or less, and even more preferably 300 seconds or less.

The oxygen concentration in the heat treatment step is less than 10.0%, preferably 5.0% or less, more preferably 1.0% or less, still more preferably 0.1% or less. If the oxygen concentration during heating is high, the resist underlayer film may be oxidized and the properties required for the resist underlayer film may not be exhibited.

In the present embodiment, the resist underlayer film is formed through the above heat treatment step. However, when the composition in the present embodiment contains a photosensitive acid generator, exposure and heating are combined. Thereby, curing can be promoted to form a resist underlayer film. The radiation used for this exposure includes electromagnetic waves such as visible light, ultraviolet rays, far ultraviolet rays, X-rays, and γ-rays; and particle beams such as electron beams, molecular beams, and ion beams, depending on the type of radiation-sensitive acid generator. It is selected as appropriate.

The lower limit of the average thickness of the resist underlayer film to be formed is preferably 0.05 μm, more preferably 0.1 μm, and even more preferably 0.2 μm. As the upper limit of the average thickness, 5 μm is preferable, 3 μm is more preferable, and 2 μm is further preferable.

<Pattern formation method>
The pattern forming method according to the present embodiment includes a step (i) of forming the resist underlayer film on the substrate by the resist underlayer film forming method according to the present embodiment, and a composition for forming an intermediate layer containing a silicon atom. A step (ii) of forming a silicon-containing intermediate layer by applying a substance on the resist lower layer film and baking it, a step of forming a resist film on the silicon-containing intermediate layer (iii), and a step of forming the resist film on the resist film. On the other hand, it includes at least a step (iv) of forming a resist pattern by exposure and development, and a step (v) of dry etching the silicon-containing intermediate layer with a gas containing fluorocarbon using the resist pattern as a mask. Since it is configured in this way, according to the pattern forming method according to the present embodiment, it is possible to form a pattern having a good shape. That is, it can be preferably applied to pattern formation using a multilayer resist process of a semiconductor device in which the pattern is further miniaturized. As the procedure of steps (ii) to (v) and the materials used in each step, for example, known materials described in JP-A-2020-30227 can be adopted.

Hereinafter, the present embodiment will be described in more detail with reference to Examples and Comparative Examples, but the present embodiment is not limited thereto.

^{1 1} H-NMR measurement was carried out under the following conditions using "Advance 600II spectrometer" manufactured by Bruker.
Frequency: 400MHz
Solvent: d6-DMSO
Internal standard: TMS
Measurement temperature: 23 ° C

(Molecular weight)
It was measured by LC-MS analysis using Water's Accuracy UPLC / MALDI-Synapt HDMS.
(Polystyrene equivalent molecular weight)
By gel permeation chromatography (GPC) analysis, the polystyrene-equivalent weight average molecular weight (Mw) and number average molecular weight (Mn) were determined, and the dispersity (Mw / Mn) was determined.
Equipment: Shodex GPC-101 type (manufactured by Showa Denko KK)
Column: KF-80M x 3
Eluent: THF 1 mL / min
Temperature: 40 ° C

(Synthesis Example 1) Synthesis of R-DHN 16.8 g (105 mmol) of 2,6-dihydroxynaphthalene (reagent manufactured by Kanto Chemical Co., Inc.) and phthalic acid in a container having an internal volume of 500 mL equipped with a stirrer, a cooling tube and a burette. 10.1 g (20 mmol) of monobutyl copper was charged, 30 mL of 1-butanol was added as a solvent, and the reaction solution was stirred at 110 ° C. for 6 hours to carry out the reaction. After cooling, the precipitate was filtered and the obtained crude was dissolved in 100 mL of ethyl acetate. Next, 5 mL of hydrochloric acid was added, and the mixture was stirred at room temperature and then neutralized with sodium hydrogen carbonate. The ethyl acetate solution was concentrated, 200 mL of methanol was added to precipitate the reaction product, the mixture was cooled to room temperature, and then filtered and separated. By drying the obtained solid substance, 27.3 g of the target resin (R-DHN) having a structure represented by the following formula was obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 3578, Mw: 4793, Mw / Mn: 1.34.
When the obtained resin was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the resin had the chemical structure of the following formula.
δ (ppm) 9.7 to 9.8 (2H, OH), 7.0 to 7.9 (4H, Ph-H)

(Synthesis Example 1-2) Synthesis of R-2,7DHN 16.8 g (105 mmol) of 2,7-dihydroxynaphthalene (reagent manufactured by Kanto Chemical Co., Inc.) is placed in a container having an internal volume of 500 mL equipped with a stirrer, a cooling tube and a burette. , 15.2 g (30 mmol) of monobutyl phthalate was charged, 40 mL of 1-butanol was added as a solvent, and the reaction solution was stirred at 110 ° C. for 6 hours to carry out the reaction. After cooling, the precipitate was filtered and the obtained crude was dissolved in 100 mL of ethyl acetate. Next, 5 mL of hydrochloric acid was added, and the mixture was stirred at room temperature and then neutralized with sodium hydrogen carbonate. The ethyl acetate solution was concentrated, 200 mL of methanol was added to precipitate the reaction product, the mixture was cooled to room temperature, and then filtered and separated. By drying the obtained solid substance, 24.7 g of the target resin (R-2,7DHN) having a structure represented by the following formula was obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 2832, Mw: 3476, Mw / Mn: 1.23.
When the obtained resin was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the resin had the chemical structure of the following formula.
δ (ppm) 9.7 to 9.8 (2H, OH), 7.0 to 7.9 (4H, Ph-H)

(Synthesis Example 1-3) Synthesis of R-2,3DHN The 2,7-dihydroxynaphthalene (reagent manufactured by Kanto Chemical Co., Inc.) in Synthesis Example 1-2 was changed to 2,3-dihydroxynaphthalene (reagent manufactured by Kanto Chemical Co., Inc.). The procedure was carried out in the same manner as in Synthesis Example 1-2 except that 29.2 g of the target resin (R-2,3DHN) having a structure represented by the following formula was obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 3124, Mw: 4433, Mw / Mn: 1.42.
When the obtained resin was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the resin had the chemical structure of the following formula.
δ (ppm) 9.5 to 9.6 (2H, OH), 7.0 to 7.9 (4H, Ph-H)

(Synthesis Example 1-4) Synthesis of R-1,5DHN The 2,7-dihydroxynaphthalene (reagent manufactured by Kanto Chemical Co., Inc.) in Synthesis Example 1-2 was changed to 1,5-dihydroxynaphthalene (reagent manufactured by Kanto Chemical Co., Inc.). The procedure was carried out in the same manner as in Synthesis Example 1-2 except that 25.8 g of the target resin (R-1,5DHN) having a structure represented by the following formula was obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 2988, Mw: 3773, and Mw / Mn: 1.26.
When the obtained resin was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the resin had the chemical structure of the following formula.
δ (ppm) 9.8 to 9.9 (2H, OH), 7.1 to 8.0 (4H, Ph-H)

(Synthesis Example 1-5) Synthesis of R-1,6DHN The 2,7-dihydroxynaphthalene (reagent manufactured by Kanto Chemical Co., Inc.) in Synthesis Example 1-2 was changed to 1,6-dihydroxynaphthalene (reagent manufactured by Kanto Chemical Co., Inc.). The procedure was carried out in the same manner as in Synthesis Example 1-2 except that 23.2 g of the target resin (R-1,6DHN) having a structure represented by the following formula was obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 2687, Mw: 3693, Mw / Mn: 1.37.
When the obtained resin was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the resin had the chemical structure of the following formula.
δ (ppm) 9.8 to 9.9 (2H, OH), 6.8 to 7.9 (4H, Ph-H)

(Synthesis Example 1-6) Synthesis of R-FLBNDHN 6,6'-(9H) in a container with an internal volume of 500 mL equipped with a stirrer, a cooling tube and a burette.
-Fluoren-9,9-diyl) bis (2-naphthol) (reagent manufactured by Kanto Chemical Co., Inc.) 47.3 g (105 mmol), 2,6-dihydroxynaphthalene (reagent manufactured by Kanto Chemical Co., Inc.) 16.8 g (105 mmol) , 10.1 g (20 mmol) of monobutyl phthalate was charged, 120 mL of 4-butyrolactone was added as a solvent, and the reaction solution was stirred at 120 ° C. for 8 hours to carry out the reaction. After cooling, the precipitate was filtered and the resulting crude was dissolved in 150 mL of ethyl acetate. Next, 5 mL of hydrochloric acid was added, and the mixture was stirred at room temperature and then neutralized with sodium hydrogen carbonate. The ethyl acetate solution was concentrated, 300 mL of distilled water was added to precipitate the reaction product, the mixture was cooled to room temperature, and then filtered and separated. By drying the obtained solid substance, 51.6 g of a target resin (R-FLBNDHN) having a structure represented by the following formula was obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 4128, Mw: 5494, Mw / Mn: 1.33.
When the obtained resin was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the resin had the chemical structure of the following formula.
δ (ppm) 9.7 to 9.9 (2H, OH), 9.1 to 9.3 (2H, OH), 7.1 to 8.0 (22H, Ph-H)

That is, R-FLBNDHN is 6,6'-(9H-fluorene-9,9-diyl).
A homopolymer of bis (2-naphthol), a homopolymer of 2,6-dihydroxynaphthalene, 6,6'-(9H-fluorene-9,9-diyl) bis (2-naphthol) and 2,
It was a mixture containing a copolymer of 6-dihydroxynaphthalene.

(Synthesis Example 2) Synthesis of R-BiF 19.2 g (105 mmol) of 4,4-biphenol (reagent manufactured by Kanto Chemical Co., Inc.) and monobutyl phthalate in a container with an internal volume of 500 mL equipped with a stirrer, a cooling tube and a burette. 10.1 g (20 mmol) of copper was charged, 80 mL of 4-butyrolactone was added as a solvent, and the reaction solution was stirred at 120 ° C. for 6 hours to carry out the reaction. After cooling, the precipitate was filtered and the obtained crude was dissolved in 100 mL of ethyl acetate. Next, 5 mL of hydrochloric acid was added, and the mixture was stirred at room temperature and then neutralized with sodium hydrogen carbonate. The ethyl acetate solution was concentrated, 200 mL of methanol was added to precipitate the reaction product, the mixture was cooled to room temperature, and then filtered and separated. By drying the obtained solid substance, 21.2 g of the target resin (R-BiF) having a structure represented by the following formula was obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 4128, Mw: 5494, Mw / Mn: 1.33.
When the obtained resin was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the resin had the chemical structure of the following formula.
δ (ppm) 9.1 to 9.3 (2H, OH), 7.1 to 8.2 (6H, Ph-H)

(Synthesis Example 3) Synthesis of BisN-1 20.0 g (200 mmol) of 1,4-dihydroxybenzene (reagent manufactured by Kanto Chemical Co., Inc.) and 4-biphenyl are placed in a container having an internal volume of 500 mL equipped with a stirrer, a cooling tube and a burette. 18.2 g (100 mmol) of aldehyde (manufactured by Mitsubishi Gas Chemical Co., Inc.) and 100 mL of 1,4-dioxane were charged, 5 mL of 95% sulfuric acid was added, and the reaction was carried out by stirring at 100 ° C. for 6 hours. Next, after neutralizing the reaction solution with a 24% aqueous sodium hydroxide solution, 50 g of pure water was added to precipitate the reaction product, the reaction product was cooled to room temperature, and then filtration was performed for separation. The obtained solid substance was dried and then separated and purified by column chromatography to obtain 20.6 g of the target compound (BisN-1) represented by the following formula.
The following peaks were found by 400 MHz- ^{1 1} H-NMR, and it was confirmed that the chemical structure had the following formula.
^{1 1} H-NMR: (d-DMSO, internal standard TMS)
δ (ppm) 9.4 (2H, O—H), 7.2 to 8.1 (13H, Ph—H), 6.5 (1H, CH)
In addition, LC-MS analysis confirmed that the molecular weight was 366.1, which corresponds to the following chemical structure.

(Synthesis Example 3-1) Synthesis of RBisN-1 38.0 g (105 mmol) of BisN-1 and 10.1 g (20 mmol) of monobutyl phthalate in a container having an internal volume of 500 mL equipped with a stirrer, a cooling tube and a burette. ) The reaction was carried out by adding 100 mL of 1-butanol as a solvent and stirring the reaction solution at 100 ° C. for 6 hours. After cooling, the precipitate was filtered and the obtained crude was dissolved in 100 mL of ethyl acetate. Next, 5 mL of hydrochloric acid was added, and the mixture was stirred at room temperature and then neutralized with sodium hydrogen carbonate. The ethyl acetate solution was concentrated, 200 mL of methanol was added to precipitate the reaction product, the mixture was cooled to room temperature, and then filtered and separated. By drying the obtained solid substance, 28.2 g of the target resin (RBisN-1) having a structure represented by the following formula was obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 3762, Mw: 4905, and Mw / Mn: 1.30.
When the obtained resin was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the resin had the chemical structure of the following formula.
δ (ppm) 9.3 to 9.6 (2H, OH), 7.2 to 8.7 (17H, Ph-H), 6.8 (1H, CH)

(Synthesis Example 4) Synthesis of BisN-2 In a container with an internal volume of 500 mL equipped with a stirrer, a cooling tube and a burette, 32.0 g (20 mmol) of 2,6-naphthalenediol (reagent manufactured by Sigma-Aldrich) and 4- 18.2 g (100 mmol) of biphenyl aldehyde (manufactured by Mitsubishi Gas Chemical Company, Inc.) and 200 mL of 1,4-dioxane were charged, 10 mL of 95% sulfuric acid was added, and the reaction was carried out by stirring at 100 ° C. for 6 hours. Next, the reaction solution was neutralized with a 24% aqueous sodium hydroxide solution, 100 g of pure water was added to precipitate the reaction product, the mixture was cooled to room temperature, and then filtered and separated. The obtained solid substance was dried and then separated and purified by column chromatography to obtain 25.5 g of the target compound (BisN-2) represented by the following formula.
The following peaks were found by 400 MHz- ^{1 1} H-NMR, and it was confirmed that the chemical structure had the following formula. Moreover, it was confirmed that the substitution position of 2,6-dihydroxynaphthol was at the 1-position because the signals of the protons at the 3-position and the 4-position were doublets.
^{1 1} H-NMR: (d-DMSO, internal standard TMS)
δ (ppm) 9.7 (2H, O—H), 7.2 to 8.5 (19H, Ph—H), 6.6 (1H, CH)
In addition, LC-MS analysis confirmed that the molecular weight was 466.5, which corresponds to the following chemical structure.

(Synthesis Example 4-1) Synthesis of RBisN-2 50 g (105 mmol) of BisN-2 and 10.1 g (20 mmol) of monobutyl phthalate are charged in a container having an internal volume of 500 mL equipped with a stirrer, a cooling tube and a burette. 100 mL of 1-butanol was added as a solvent, and the reaction solution was stirred at 100 ° C. for 6 hours to carry out the reaction. After cooling, the precipitate was filtered and the obtained crude was dissolved in 100 mL of ethyl acetate. Next, 5 mL of hydrochloric acid was added, and the mixture was stirred at room temperature and then neutralized with sodium hydrogen carbonate. The ethyl acetate solution was concentrated, 200 mL of methanol was added to precipitate the reaction product, the mixture was cooled to room temperature, and then filtered and separated. By drying the obtained solid substance, 38.2 g of the target resin (RBisN-2) having a structure represented by the following formula was obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 4232, Mw: 5502, Mw / Mn: 1.30.
When the obtained resin was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the resin had the chemical structure of the following formula.
δ (ppm) 9.3 to 9.7 (2H, OH), 7.2 to 8.5 (17H, Ph-H), 6.7 to 6.9 (1H, CH)

(Synthesis Example 4A) Synthesis of BisN-5 4-biphenylaldehyde (manufactured by Mitsubishi Gas Chemical Company, Inc.) 18.2 g (100 mmol) of Synthesis Example 4 to 9.1 g (100 mmol) of 4-toluylaldehyde (manufactured by Mitsubishi Gas Chemical Company, Inc.) The same operation as in Synthesis Example 4 was carried out except for the changes, and 23.2 g of the target compound (BisN-3) represented by the following formula was obtained.
The following peaks were found by 400 MHz- ^{1 1} H-NMR, and it was confirmed that the chemical structure had the following formula. Moreover, it was confirmed that the substitution position of 2,6-dihydroxynaphthol was at the 1-position because the signals of the protons at the 3-position and the 4-position were doublets.
^{1 1} H-NMR: (d-DMSO, internal standard TMS)
δ (ppm) 9.7 (2H, O—H), 7.2 to 8.4 (14H, Ph—H), 6.6 (1H, CH), 1.9 (3H, C—H3) )
In addition, LC-MS analysis confirmed that the molecular weight was 404.1, which corresponds to the following chemical structure.

(Synthesis Example 4A-1) Synthesis of RBisN-5 The following formula is the same as that of Synthesis Example 4-1 except that BisN-2 of Synthesis Example 4-1 is changed to BisN-5 obtained in Synthesis Example 4A. 32.1 g of the target resin (RBisN-5) having the structure represented by is obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 3452, Mw: 4802, Mw / Mn: 1.39.
When the obtained resin was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the resin had the chemical structure of the following formula.
δ (ppm) 9.3 to 9.7 (2H, OH), 7.2 to 8.5 (12H, Ph-H), 6.7 to 6.9 (1H, CH), 1 .9 (3H, C-H3)

(Synthesis Example 4B) Synthesis of BisN-6 4-biphenylaldehyde (manufactured by Mitsubishi Gas Chemical Company, Inc.) 18.2 g (100 mmol) of Synthesis Example 4 was converted to 4-cyclohexylbenzaldehyde (manufactured by Mitsubishi Gas Chemical Company, Inc.) to 18.8 g (100 mmol). The same operation as in Synthesis Example 4 was carried out except for the changes, and 33.5 g of the target compound (BisN-6) represented by the following formula was obtained.
The following peaks were found by 400 MHz- ^{1 1} H-NMR, and it was confirmed that the chemical structure had the following formula. Moreover, it was confirmed that the substitution position of 2,6-dihydroxynaphthol was at the 1-position because the signals of the protons at the 3-position and the 4-position were doublets.
^{1 1} H-NMR: (d-DMSO, internal standard TMS)
δ (ppm) 9.7 (2H, O—H), 7.2 to 8.4 (14H, Ph—H), 6.6 (1H, CH), 2.5 to 2.6 (6H) , C6-H5)
In addition, LC-MS analysis confirmed that the molecular weight was 472.2, which corresponds to the following chemical structure.

(Synthesis Example 4B-1) Synthesis of RBisN-6 The following formula is the same as that of Synthesis Example 4-1 except that BisN-2 of Synthesis Example 4-1 was changed to BisN-6 obtained in Synthesis Example 4B. 40.4 g of the target resin (RBisN-6) having the structure represented by is obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 3672, Mw: 5080, Mw / Mn: 1.38.
When the obtained resin was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the resin had the chemical structure of the following formula.
δ (ppm) 9.3 to 9.7 (2H, OH), 7.2 to 8.5 (12H, Ph-H), 6.7 (1H, CH), 2.5 to 2 .7 (6H, C6-H5)

(Synthesis Example 4C) Synthesis of BisN-7 4-biphenylaldehyde (manufactured by Mitsubishi Gas Chemical Co., Inc.) 18.2 g (100 mmol) of Synthesis Example 4 was changed to 2-naphthaldehyde (manufactured by Kanto Chemical Co., Inc.) g (100 mmol). The same operation as in Synthesis Example 4 was carried out except for the above, and the aromatic hydroxy compound of Synthesis Example 4C was synthesized. 33.5 g of the target resin (RBisN-7) represented by the following formula was obtained in the same manner as in Synthesis Example 4-1 except that the aromatic hydroxy compound was used.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 4174, Mw: 5280, Mw / Mn: 1.26.
The following peaks were found by 400 MHz- ^{1 1} H-NMR, and it was confirmed that the chemical structure had the following formula. Moreover, it was confirmed that the substitution position of 2,6-dihydroxynaphthol was at the 1-position because the signals of the protons at the 3-position and the 4-position were doublets.
^{1 1} H-NMR: (d-DMSO, internal standard TMS)
δ (ppm) 9.6 (2H, O-H), 7.0-8.5 (19H, Ph-H), 6.6 (1H, CH), 2.5H, Ph-H), 6.7 (1H, CH)

(Synthesis Example 5) Synthesis of BiF-1 A container having an internal volume of 1 L equipped with a stirrer, a cooling tube and a burette was prepared. In this container, 150 g (800 mmol) of 4,4-biphenol (reagent manufactured by Tokyo Kasei Co., Ltd.), 75 g (410 mmol) of 4-biphenylaldehyde (manufactured by Mitsubishi Gas Chemical Co., Inc.), and 300 mL of propylene glycol monomethyl ether are charged, and p-. A reaction solution was prepared by adding 19.5 g (105 mmol) of toluenesulfonic acid (reagent manufactured by Kanto Chemical Co., Inc.). The reaction was carried out by stirring the reaction solution at 90 ° C. for 3 hours. Next, the reaction solution was neutralized with a 24% aqueous sodium hydroxide solution, 100 g of distilled water was added to precipitate the reaction product, the mixture was cooled to 5 ° C., and then filtered and separated. The solid obtained by filtration was dried and then separated and purified by column chromatography to obtain 25.8 g of the target compound (BiF-1) represented by the following formula.
The following peaks were found by 400 MHz- ^{1 1} H-NMR, and it was confirmed that the chemical structure had the following formula.
^{1 1} H-NMR: (d-DMSO, internal standard TMS)
δ (ppm) 9.4 (4H, O—H), 6.8 to 7.8 (22H, Ph—H), 6.2 (1H, CH)
In addition, LC-MS analysis confirmed that the molecular weight was 536.2, which corresponds to the following chemical structure.

(Synthesis Example 5-1) Synthesis of RBiF-1 55.0 g (105 mmol) of BiF-1 and 10.1 g (20 mmol) of monobutyl phthalate in a container having an internal volume of 500 mL equipped with a stirrer, a cooling tube and a burette. After charging, 100 mL of 1-butanol was added as a solvent, and the reaction solution was stirred at 100 ° C. for 6 hours to carry out the reaction. After cooling, the precipitate was filtered and the obtained crude was dissolved in 100 mL of ethyl acetate. Next, 5 mL of hydrochloric acid was added, and the mixture was stirred at room temperature and then neutralized with sodium hydrogen carbonate. The ethyl acetate solution was concentrated, 200 mL of methanol was added to precipitate the reaction product, the mixture was cooled to room temperature, and then filtered and separated. By drying the obtained solid substance, 34.3 g of the target resin (RBiF-1) having a structure represented by the following formula was obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 4532, Mw: 5698, Mw / Mn: 1.26.
When the obtained resin was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the resin had the chemical structure of the following formula.
δ (ppm) 9.4 to 9.7 (4H, OH), 6.8 to 8.1 (20H, Ph-H), 6.3 to 6.5 (1H, CH)

(Synthesis Example 5A) Synthesis of BiF-3 Synthesis Example 5 except that 75 g (410 mmol) of 4-biphenylaldehyde (manufactured by Mitsubishi Gas Chemical Company, Inc.) of Synthesis Example 5 was changed to 4-toluylaldehyde (manufactured by Mitsubishi Gas Chemical Company, Inc.). In the same manner as above, 26.3 g of the target compound (BiF-3) represented by the following formula was obtained.
The following peaks were found by 400 MHz- ^{1 1} H-NMR, and it was confirmed that the chemical structure had the following formula.
^{1 1} H-NMR: (d-DMSO, internal standard TMS)
δ (ppm) 9.4 (4H, O—H), 6.8 to 7.8 (18H, Ph—H), 6.2 (1H, CH), 1.8 (3H, C—H3) )
In addition, LC-MS analysis confirmed that the molecular weight was 474.5, which corresponds to the following chemical structure.

(Synthesis Example 5A-1) Synthesis of RBiF-3 The following formula is applied in the same manner as in Synthesis Example 5-1 except that BiF-1 of Synthesis Example 5-1 is changed to BiF-3 obtained in Synthesis Example 5A. 31.2 g of the target resin (RBiF-3) having the structure represented by is obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 4232, Mw: 5288, Mw / Mn: 1.25.
When the obtained resin was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the resin had the chemical structure of the following formula.
δ (ppm) 9.4 to 9.7 (4H, OH), 6.8 to 8.1 (16H, Ph-H), 6.3 to 6.5 (1H, CH), 1 8.8 to 1.9 (3H, C-H3)

(Synthesis Example 5B) Synthesis of BiF-4 Synthesis Example 5 except that 75 g (410 mmol) of 4-biphenylaldehyde (manufactured by Mitsubishi Gas Chemical Company, Inc.) of Synthesis Example 5 was changed to 4-cyclohexylbenzaldehyde (manufactured by Mitsubishi Gas Chemical Company, Inc.). In the same manner as above, 32.1 g of the target compound (BiF-4) represented by the following formula was obtained.
The following peaks were found by 400 MHz- ^{1 1} H-NMR, and it was confirmed that the chemical structure had the following formula.
^{1 1} H-NMR: (d-DMSO, internal standard TMS)
δ (ppm) 9.4 (4H, O—H), 6.8 to 7.8 (18H, Ph—H), 6.2 (1H, CH), 2.4 to 2.6 (10H) , C6H10)
In addition, LC-MS analysis confirmed that the molecular weight was 542.7, which corresponds to the following chemical structure.

(Synthesis Example 5B-1) Synthesis of RBiF-4 The following formula is applied in the same manner as in Synthesis Example 5-1 except that BiF-1 of Synthesis Example 5-1 is changed to BiF-4 obtained in Synthesis Example 5B. 29.5 g of the target resin (RBiF-4) having the structure represented by is obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 4431, Mw: 5568, Mw / Mn: 1.26.
When the obtained resin was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the resin had the chemical structure of the following formula.
δ (ppm) 9.4 to 9.7 (4H, OH), 6.8 to 8.1 (16H, Ph-H), 6.3 to 6.5 (1H, CH), 2 .4 to 2.9 (10H, C6H10)

(Synthesis Example 5C) Synthesis of BiF-5 Synthesis Example 5 except that 75 g (410 mmol) of 4-biphenylaldehyde (manufactured by Mitsubishi Gas Chemical Company, Inc.) of Synthesis Example 5 was changed to 2-naphthaldehyde (manufactured by Mitsubishi Gas Chemical Company, Inc.). In the same manner as above, 33.5 g of the target compound (BiF-5) represented by the following formula was obtained.
The following peaks were found by 400 MHz- ^{1 1} H-NMR, and it was confirmed that the chemical structure had the following formula.
^{1 1} H-NMR: (d-DMSO, internal standard TMS)
δ (ppm) 9.4 (4H, O—H), 6.8 to 7.8 (21H, Ph—H), 6.2 (1H, CH)
In addition, LC-MS analysis confirmed that the molecular weight was 510.6, which corresponds to the following chemical structure.

(Synthesis Example 5C-1) Synthesis of RBiF-5 The following formula is the same as that of Synthesis Example 5-1 except that BiF-1 of Synthesis Example 5-1 is changed to BiF-5 obtained in Synthesis Example 5C. 29.5 g of the target resin (RBiF-4) having the structure represented by is obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 4133, Mw: 5462, Mw / Mn: 1.32.
When the obtained resin was subjected to NMR measurement under the above measurement conditions, the following peaks were found, and it was confirmed that the resin had the chemical structure of the following formula.
δ (ppm) 9.4 to 9.7 (4H, OH), 6.8 to 8.1 (19H, Ph-H), 6.3 to 6.5 (1H, CH)

(Example 5D) Synthesis of TriF-4 A container having an internal volume of 1000 mL equipped with a stirrer, a cooling tube and a burette was prepared. In this container, 10 g (53.7 mmol) of 4,4-biphenol (reagent manufactured by Tokyo Kasei Co., Ltd.), 98 g (538 mmol) of 4-biphenylaldehyde (manufactured by Mitsubishi Gas Chemical Co., Inc.), and 400 mL of propylene glycol monomethyl ether were charged. 2.7 g (26.9 mmol) of concentrated sulfuric acid (96% by mass, reagent manufactured by Kanto Chemical Co., Inc.) was added to prepare a reaction solution. The reaction was carried out by stirring this reaction solution at 100 ° C. for 5 hours. Next, the reaction solution was poured into 2 L of ion-exchanged water to precipitate the reaction product, and the mixture was cooled to room temperature. Then, 49 g (26.7 mmol) of an aqueous sodium hydroxide solution (24% by mass) was added to neutralize the mixture, and the mixture was filtered and separated. The solid obtained by filtration was dried, then dissolved in 400 mL of butyl acetate, and washed 6 times with 400 mL of an aqueous sodium carbonate solution (5% by mass). Toluene (400 mL) was added to the washed organic layer, and the mixture was stirred and then concentrated under reduced pressure at 100 ° C. to recover the precipitated solid by filtration. The obtained solid material was dried under reduced pressure to obtain 72 g of the target resin (TriF-4) represented by the following formula.
As a result of measuring the polystyrene-equivalent molecular weight by the above method, it was Mn: 4523, Mw: 5642, Mw / Mn: 1.24.
The following peaks were found by 400MHz- ^{1 1} H-NMR.
^{1 1} H-NMR: (d-DMSO, internal standard TMS)
δ (ppm) 9.3 to 9.4 (8.3H, OH), 6.7 to 7.7 (50.2H, Ph-H), 6.0 to 6.2 (3.2H, CH)

From the above ¹ H-NMR and LC-MS results, it was confirmed that the target resin obtained in Example 5 was a resin having a chemical structure of the following formula.

(Synthesis Example 6) Synthesis of DB-1 (a) Production of dibenzocrisen sulfonic acid calcium salt 20 g (0.06 mol, HPLC) of dibenzo [g, p] crisen in a 4-necked flask with a capacity of 1 L equipped with a mechanical stirrer. Purity: 99.8%) and 95% sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd.) 200 g (1.94 mol) are charged, and the mixture is kept warm using a hot water bath while stirring at an internal temperature of 80 ° C. for 2 hours. It was reacted. As a result, the content became a uniform gray viscous liquid.
400 g of distilled water was added while cooling the flask containing the contents obtained above in an ice bath. At the time of this addition, the addition was carried out while maintaining the internal temperature of 40 ° C. or lower while measuring the temperature so that the internal temperature did not exceed 40 ° C. due to heat generation. Next, 154.4 g (2.08 mol) of powdered calcium hydroxide (manufactured by Wako Pure Chemical Industries, Ltd.) was added to the flask to which the distilled water was added. At the time of this addition, the addition was carried out while maintaining the internal temperature of 45 ° C. or lower while measuring the temperature so that the internal temperature did not exceed 45 ° C. due to heat generation. By this addition, calcium sulfate was precipitated as a white solid, and the content became a slurry. Moreover, the liquid property was alkaline.
The slurry obtained above was mixed with a stainless steel Buchner funnel and No. 2 The filtrate (pale yellow liquid) obtained by suction filtration using filter paper was recovered. Further, the solid content residue (mainly calcium sulfate) was washed with 350 g of distilled water, and the washing liquid was also recovered and concentrated under reduced pressure using a rotary evaporator together with the above filtrate and the above filtrate. As a result, 36.5 g of a calcium salt of dibenzochrysene sulfonic acid, which is a pale yellow powdery solid, was obtained (yield 82.7%). Based on the results of LC / MS analysis of hydroxydibenzochrycene, which will be described later, the calcium dibenzochrysen sulfonic acid salt is a mixture in which 98% is 4-substituted dibenzochrycene sulfonate and the balance is 3-substituted dibenzochrysen sulfonate. Conceivable.
(B) Production of hydroxydibenzochrysene 85% potassium hydroxide granules (manufactured by Wako Pure Chemical Industries, Ltd.) 14.0 g (0.212 mol) were placed in a cylindrical container made of nickel having a volume of 100 mL, and a hot plate (400) was placed. ° C) and heat-melted. Subsequently, 4.0 g (0.0055 mol) of the calcium salt (mixture 8) obtained above was added. At the time of this addition, the calcium salt of dibenzochrysene sulfonic acid was put into the above-mentioned nickel tubular container over 30 minutes, and the reaction was promoted by stirring with a stainless steel spoon at the time of putting. Further, stirring was continued for 30 minutes after the addition of the calcium salt of dibenzochrysene sulfonic acid was completed. As a result, a reddish brown viscous liquid was obtained.
The reddish brown viscous liquid obtained above (the contents of the nickel tubular container) was poured into a stainless steel volume 200 mL cup while hot and solidified by cooling. Subsequently, 40 g of distilled water was added to the stainless steel cup to dissolve the solid matter in water to obtain a reddish brown slightly turbid liquid.
Next, the reddish brown liquid is transferred to a glass volume 200 mL beaker, and 35% hydrochloric acid (Wako Pure Chemical Industries, Ltd.) is added while stirring using a magnetic stirrer to prepare the content containing a brown solid. Obtained. At the time of this addition, the addition was continued until the pH of the contents reached pH 3 while measuring the pH with a pH meter. It was confirmed that the brown solid was precipitated at the time of neutralization.
Then, 30 g of ethyl acetate (Wako Pure Chemical Industries, Ltd.) was added to the contents obtained so far and stirred to dissolve the brown solid. Then, the obtained liquid was allowed to stand to be separated into an organic phase and an aqueous phase, and then the organic phase was separated. The separated organic layer was made of glass roth and No. 2 After filtering with a filter paper to remove insoluble matters, the mixture was concentrated under reduced pressure using a rotary evaporator to obtain 1.6 g of a brown powdery solid (yield 73.9%). As a result of subjecting the brown powdery solid obtained by the above operation to LC / MS analysis, the brown powdery solid was 4-substituted hydroxydibenzochrysene having a purity of 98%.

(Synthesis Example 6-1) Synthesis of RDB-1 In a container having an internal volume of 500 mL equipped with a stirrer, a cooling tube and a burette, 80.0 g of DB-1 and 10.1 g (20 mmol) of monobutyl phthalate are charged, and a solvent is added. As a result, 100 mL of 1-butanol was added, and the reaction solution was stirred at 100 ° C. for 6 hours to carry out the reaction. After cooling, the precipitate was filtered and the obtained crude was dissolved in 100 mL of ethyl acetate. Next, 5 mL of hydrochloric acid was added, and the mixture was stirred at room temperature and then neutralized with sodium hydrogen carbonate. The ethyl acetate solution was concentrated, 300 mL of heptane was added to precipitate the reaction product, the mixture was cooled to room temperature, and then filtered and separated. By drying the obtained solid substance, 64.5 g of the target resin (RDB-1) having a structure represented by the group represented by the following formula was obtained.
As a result of measuring the polystyrene-equivalent molecular weight of the obtained resin by the above method, it was Mn: 2512, Mw: 3298, Mw / Mn: 1.31.

(Comparative synthesis example 1)
A four-necked flask with an internal volume of 10 L, which was equipped with a Dimroth condenser, a thermometer, and a stirring blade, was prepared. In this four-necked flask, 1.09 kg of 1,5-dimethylnaphthalene (7 mol, manufactured by Mitsubishi Gas Chemical Company, Inc.) and 2.1 kg of 40 mass% formalin aqueous solution (28 mol as formaldehyde, Mitsubishi Gas Chemical Company, Inc.) in a nitrogen stream. ) And 98% by mass sulfuric acid (manufactured by Kanto Chemical Co., Inc.) were charged and reacted for 7 hours under normal pressure while refluxing at 100 ° C. Then, 1.8 kg of ethylbenzene (special grade reagent manufactured by Wako Pure Chemical Industries, Ltd.) was added to the reaction solution as a diluting solvent, and after standing, the aqueous phase of the lower phase was removed. Further, the mixture was neutralized and washed with water, and ethylbenzene and unreacted 1,5-dimethylnaphthalene were distilled off under reduced pressure to obtain 1.25 kg of a light brown solid dimethylnaphthalene formaldehyde resin.

Subsequently, a four-necked flask having an internal volume of 0.5 L equipped with a Dimroth condenser, a thermometer and a stirring blade was prepared. In this four-necked flask, 100 g (0.51 mol) of dimethylnaphthalene formaldehyde resin obtained as described above and 0.05 g of p-toluenesulfonic acid were charged under a nitrogen stream, and the temperature was raised to 190 ° C. 2 After heating for hours, the mixture was stirred. After that, 52.0 g (0.36 mol) of 1-naphthol was further added, the temperature was further raised to 220 ° C., and the reaction was carried out for 2 hours. After diluting the solvent, it was neutralized and washed with water, and the solvent was removed under reduced pressure to obtain 126.1 g of a dark brown solid modified resin (CR-1).

<Formation of resist underlayer film>
[Example]
Compositions for forming each resist underlayer film were prepared from the resins obtained in the synthetic examples so as to have the compositions shown in Tables 1 and 2, and were applied onto a silicon wafer substrate by a spin coating method. Then, under a predetermined oxygen concentration atmosphere, the mixture was allowed to stand for 60 seconds without being in contact with the hot plate, and then a preliminary heat treatment was performed on the hot plate at 200 ° C. to 300 ° C. for 60 seconds (Tables 1 and 2 respectively). The conditions are shown.) A resist underlayer film precursor having an average thickness of 200 nm was formed on the substrate. Then, under a low oxygen concentration atmosphere (oxygen concentration less than 5.0%), heat treatment (baking) was performed at 550 to 750 ° C. for 120 seconds (each condition is shown in Tables 1 and 2), and a resist underlayer film was attached. Obtained a substrate.

[Comparison example]
Similarly, the compositions for forming each resist underlayer film were prepared so as to have the compositions shown in Tables 3 to 4, and were applied onto the silicon wafer substrate by the spin coating method. Then, in a predetermined oxygen concentration atmosphere, the mixture is allowed to stand for 60 seconds without being in contact with the hot plate, and then preheated on the hot plate at 320 to 350 ° C. for 60 seconds, and 550 to 800 under each oxygen concentration condition. A substrate with a resist underlayer film was obtained by heat-treating (baking) at ° C. for 120 seconds.

Separately, for heat resistance evaluation, a resist underlayer film forming composition prepared so as to have the same composition as each Example and Comparative Example was applied onto a silicon wafer substrate by a spin coating method, and then preheat treatment was not performed and the atmosphere was not subjected to preheat treatment. The substrate was heated (baked) at 400 ° C. for 60 seconds in an atmosphere to obtain a substrate with a resist underlayer film for heat resistance evaluation.

The following were used as the organic solvent and the novolak resin.
Organic solvent: cyclohexanone (CHN), propylene glycol monomethyl ether acetate (PGMEA)
Novolac resin: PSM4357 manufactured by Gun Ei Chemical Industry Co., Ltd.

Various evaluations were performed on the obtained substrate with a resist underlayer film according to the following procedure. The evaluation results are shown in Tables 1 and 2 below together with the firing conditions.

[Heat-resistant]
The film thickness of the obtained substrate with a resist underlayer film is measured after heating (baking) using an interferometry film thickness meter, and the film thickness is relative to the film thickness of the above-mentioned substrate with a resist underlayer film for heat resistance evaluation. The thickness reduction rate was calculated. The heat resistance is "A" (extremely good) when the film thickness reduction rate is less than 20%, "B" (good) when the film thickness reduction rate is 20% or more and less than 40%, and "C" when the film thickness reduction rate is 40% or more. "(Defective) was evaluated.

[Evaluation of etching resistance]
The etching resistance was evaluated by the following procedure.
First, novolak (PSM4357 manufactured by Gun Ei Chemical Industry Co., Ltd.) was used instead of the resin used in the examples, and the firing conditions were that the resin was heated (baked) at 400 ° C. for 60 seconds in an air atmosphere without performing preliminary heat treatment. Under the same conditions as in the examples, a novolak underlayer film for etching resistance evaluation was prepared. Then, an etching test was performed on the underlayer film of this novolak under the following conditions, and the etching rate at that time was measured.
[Etching conditions]
Etching device: RIE-10NR manufactured by SAMCO International Corporation
Output: 50W
Pressure: 20Pa
Time: 2min
Etching gas Ar gas flow rate: CF ₄ gas flow rate: O ₂ gas flow rate = 50: 5: 5 (sccm)

Next, the above etching test was carried out in the same manner for the lower layer films of Examples and Comparative Examples, and the etching rate at that time was measured.
Then, based on the etching rate obtained from the underlayer film of Novolac for evaluation of etching resistance, the etching resistance was evaluated according to the following evaluation criteria.
[Evaluation criteria]
A: Etching rate is less than -10% compared to Novolac underlayer B: Etching rate is -10% to + 5% compared to Novolac underlayer.
C: Etching rate is over + 5% compared to the underlayer film of Novolac

[Carbon concentration]
The carbon concentration was measured by organic elemental analysis.
Equipment: CHN coder MT-6 (manufactured by Yanaco Analytical Industry Co., Ltd.)
[Evaluation criteria]
A: 89.0% by mass or more B: less than 89.0% by mass

As can be seen from the results in Tables 1 and 2, according to the resist underlayer film forming method of the example, the heating temperature in the preliminary heat treatment step and the oxygen concentration and the heating temperature in the heating step are adjusted to desired ranges. It was possible to form a resist underlayer film having excellent heat resistance and etching resistance. On the other hand, in the comparative examples shown in Tables 3 to 4, since either the heating temperature in the preheat treatment step or the oxygen concentration or the heating temperature in the heating step is out of the desired range, the etching resistance becomes poor and the heating is performed. It was also found that the carbon concentration after the process did not meet the preferable range. There was also a tendency for the heat resistance to decrease.

The method for forming a resist underlayer film of the present invention can form a resist underlayer film having excellent etching resistance. Further, in the pattern forming method of the present invention, a pattern having a good shape can be formed by using the resist underlayer film having excellent etching resistance described above. Therefore, these can be suitably used for pattern formation using the multilayer resist process of the semiconductor device in which the pattern is further miniaturized.

Claims (24)

A step of applying a composition containing a material for forming a resist underlayer film selected from the group consisting of an aromatic compound or a resin thereof onto a substrate, and a step of applying the composition.
A preheat treatment step of heating the applied composition at 50 ° C. or higher and 300 ° C. or lower, and
After the preheat treatment step, a heat treatment step of heating at a temperature of 400 ° C. or higher and lower than 800 ° C. in an inert gas atmosphere having an oxygen concentration of less than 5%
A method for forming a resist underlayer film, including. The method for forming a resist underlayer film according to claim 1, wherein in the preheat treatment step, the composition is heated in an atmosphere of an inert gas having an oxygen concentration of less than 5%. The invention according to claim 1 or 2, wherein the aromatic compound is a compound represented by the following formula (1A), and / or the resin is a resin having a structure represented by the following formula (2A). Method of forming a resist underlayer film.

(In the formula (1A), X is an oxygen atom, a sulfur atom, a single bond or no cross-linking, R ^a is a 2n-valent group or a single bond having 1 to 40 carbon atoms, and R ^b is independent of each other. An alkyl group having 1 to 40 carbon atoms which may have a substituent, an aryl group having 6 to 40 carbon atoms which may have a substituent, and 2 to 40 carbon atoms which may have a substituent. An alkenyl group, an alkynyl group having 2 to 40 carbon atoms which may have a substituent, an alkoxy group having 1 to 40 carbon atoms which may have a substituent, a halogen atom, a thiol group or a hydroxyl group. m is an independently integer of 0 to 9, n is an integer of 1 to 4, and p is an independently of an integer of 0 to 2. where at least one of R ^b is a hydroxyl group and It is a group containing one selected from thiol groups, and not all m becomes 0 at the same time.)

(In the formula (2A), X, R ^a , R ^b , n and p are synonymous with those described in the above formula (1A), and R ^c is a single bond or an alkylene group having 1 to 40 carbon atoms. , M ² are independently integers from 0 to 8. Here, at least one of R ^b is a group containing at least one selected from a hydroxyl group and a thiol group, and all m ² are simultaneously. It will never be 0.) The resin is a polycyclic polyphenol resin having a repeating unit derived from an aromatic hydroxy compound represented by the formula (1B), and the repeating units are linked by a direct bond between the aromatic rings. The method for forming a resist underlayer film according to claim 1 or 2, which comprises a polyphenol resin.

(In the formula (1B), A represents a benzene ring or a condensed ring. Further, R ⁰ independently has an alkyl group having 1 to 40 carbon atoms and a substituent which may have a substituent. An aryl group having 6 to 40 carbon atoms which may be present, an alkenyl group having 2 to 40 carbon atoms which may have a substituent, an alkynyl group having 2 to 40 carbon atoms which may have a substituent, and a substituent. It is an alkoxy group, a halogen atom, a thiol group or a hydroxyl group having 1 to 40 carbon atoms which may have a group, where at least one of R ⁰ is a hydroxyl group and m is an integer of 0 to 9. .) The method for forming a resist underlayer film according to claim 3, wherein the compound represented by the formula (1A) is a compound represented by the following formula (1).

(In the formula (1), X, m, n and p are synonymous with those described in the above formula (1A), R ¹ is synonymous with R ^a in the above formula (1A), and R ² is independent of each other. An alkyl group having 1 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a halogen atom, a thiol group or a hydroxyl group. At least one of R ² is a hydroxyl group or a thiol group, and not all m are zero at the same time.) The method for forming a resist underlayer film according to claim 5, wherein the compound represented by the formula (1) is a compound represented by the following formula (1-1).

(In the formula (1-1), Z is an oxygen atom or a sulfur atom, and R ¹ , R ² , m, p and n are synonymous with those described in the above formula (1). Here, R ² is used. At least one of them is one selected from a hydroxyl group and a thiol group, and not all m becomes 0 at the same time.) The method for forming a resist underlayer film according to claim 6, wherein the compound represented by the formula (1-1) is a compound represented by the following formula (1-2).

(In the formula (1-2), R ¹ , R ² , m, p and n are synonymous with those described in the above formula (1). Here, at least one of R ² is a hydroxyl group or a thiol group. Yes, not all m's are 0 at the same time.) The method for forming a resist underlayer film according to claim 7, wherein the compound represented by the formula (1-2) is a compound represented by the following formula (1-3).

(In the formula (1-3), R ¹ , p and n are synonymous with those described in the above formula (1), and R ⁴ is an alkyl group having 1 to 40 carbon atoms and the number of carbon atoms, respectively. It is an aryl group of 6 to 40, an alkenyl group having 2 to 40 carbon atoms, an alkynyl group having 2 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a halogen atom or a thiol group, and m ⁴ is independent of each other. It is an integer of 0 to 8, and q is an integer of 0 to 8 independently. Here, not all qs are 0 at the same time.) The method for forming a resist underlayer film according to claim 8, wherein the compound represented by the formula (1-3) is a compound represented by the following formula (1-4).

(In the formula (1-4), R ¹ , p and n are synonymous with those described in the above formula (1), and R ⁴ is synonymous with the one described in the above formula (1-3). ⁴ ′ is an integer of 0 to 7 independently.) The method for forming a resist underlayer film according to claim 9, wherein the compound represented by the formula (1-4) is a compound represented by the following formula (1-5).

(In the above formula (1-5), R ¹ is synonymous with the one described in the above formula (1), and R ⁴ is synonymous with the one described in the above formula (1-3), m ⁴ ″. Are independently integers from 0 to 5.) The method for forming a resist underlayer film according to claim 3, wherein the compound represented by the formula (1A) is a compound represented by the following formula (3).

(In the formula (3), R ¹ is synonymous with R ^a in the formula (1A), n and p are synonymous with those described in the formula (1A), and R ⁵ and R ⁶ are independent of each other. It is an alkyl group having 1 to 40 carbon atoms, an aryl group having 6 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a halogen atom, a thiol group or a hydroxyl group, and m ⁵ is Each is an independently integer from 0 to 8, and m ⁶ is an independent integer from 0 to 9. where at least one selected from R ⁵ and R ⁶ is selected from a hydroxyl group and a thiol group. It is a species, and not all m ⁵ and m ⁶ are 0 at the same time.) The method for forming a resist underlayer film according to claim 11, wherein the compound represented by the formula (3) is a compound represented by the following formula (3-1).

(In Eq. (3-1), R ¹ , R ⁵ , R ⁶ and n are synonymous with those described in Eq. (3), and m ^5'is an integer of 0 to 4 independently. , M ^6'are independently integers from 0 to 5. where at least one selected from R ⁵ and R ⁶ is one selected from hydroxyl and thiol groups, all m ^5'and. m ^6'cannot be 0 at the same time.) The method for forming a resist underlayer film according to claim 12, wherein the compound represented by the formula (3-1) is a compound represented by the following formula (3-2).

(In the formula (3-2), R ¹ has the same meaning as that described in the above formula (3), and R ⁷ and R ⁸ are independently alkyl groups having 1 to 40 carbon atoms and 6 to 40 carbon atoms, respectively. Aryl group, alkenyl group having 2 to 40 carbon atoms, alkynyl group having 2 to 40 carbon atoms, alkoxy group having 1 to 40 carbon atoms, halogen atom, thiol group or hydroxyl group, and m ⁷ and m ⁸ are independent of each other. It is an integer from 0 to 7.) The method for forming a resist underlayer film according to claim 3, wherein the resin having the structure represented by the formula (2A) is a resin having the structure represented by the following formula (2).

(In the formula (2), X, R ¹ , R ² , n and p are synonymous with those described in the above formula (1), R ³ is synonymous with R ^c in the above formula (2A), and m. ² is synonymous with that described in the above formula (2A). Here, at least one of R ² is one selected from a hydroxyl group and a thiol group, and all m ² are not 0 at the same time. .) The method for forming a resist underlayer film according to claim 14, wherein the resin having the structure represented by the formula (2) is a resin having the structure represented by the following formula (2-1).

(In the formula (2-1), Z has the same meaning as that described in the above formula (1-1), and R ¹ , R ² , R ³ , m ² , p and n are described in the above formula (2). Here, at least one of R ² is one selected from a hydroxyl group and a thiol group, and not all m ² become 0 at the same time.) ^{14 .} The method for forming a resist underlayer film according to the above. The method for forming a resist underlayer film according to claim 3, wherein the resin having the structure represented by the formula (2A) is a resin having the structure represented by the following formula (4).

(In the formula (4), R ¹ , p and n are synonymous with those described in the above formula (2A), and R ⁵ and R ⁶ are independently alkyl groups having 1 to 40 carbon atoms and carbon atoms, respectively. It is an aryl group of 6 to 40, an alkenyl group having 2 to 40 carbon atoms, an alkoxy group having 1 to 40 carbon atoms, a halogen atom, a thiol group or a hydroxyl group, and m ⁵ is an independently integer of 0 to 8. m ⁶ is an independently integer from 0 to 9. Here, at least one selected from R ⁵ and R ⁶ is one selected from a hydroxyl group and a thiol group, and all m ⁵ and m ⁶ are selected. It does not become 0 at the same time. R ³ is synonymous with R ^c in the above equation (2A).) The method for forming a resist underlayer film according to claim 17, wherein in the resin having the structure represented by the formula (4), R ³ is a single bond and the aromatic rings are directly bonded to each other by the R ³ . .. The ^RA or ^{R 1} is a group represented by RA ^- RB, where the ^RA is a methine group, and the ^RB may have a substituent and has 6 carbon atoms. The method for forming a resist underlayer film according to any one of claims 3 and 5 to 18, which is an aryl group of about 30. The method for forming a resist underlayer film according to claim 4, wherein A in the formula (1B) is a condensed ring. The method for forming a resist underlayer film according to any one of claims 1 to 20, wherein the resin further has a modified portion derived from a crosslink-reactive compound. The method for forming a resist underlayer film according to claim 21, wherein the crosslinkable compound is an aldehyde or a ketone. The method for forming a resist underlayer film according to any one of claims 1 to 22, wherein the resin has a weight average molecular weight of 1000 to 100,000. A step of forming the resist underlayer film on the substrate by the method for forming the resist underlayer film according to any one of claims 1 to 23.
A step of applying a composition for forming an intermediate layer containing a silicon atom onto the resist underlayer film and baking the composition to form a silicon-containing intermediate layer.
The step of forming a resist film on the silicon-containing intermediate layer and
A step of forming a resist pattern by at least exposing and developing the resist film.
A step of dry etching the silicon-containing intermediate layer using a gas containing fluorocarbon using the resist pattern as a mask.
A pattern forming method including.